[music playing] HUNTER ELLIS (VOICEOVER): This week, join me as I try to unlock the secrets of one of the strangest archaeological discoveries ever made-- colossal heads, 3,000 years old, carved at the dawn of civilization in Mesoamerica. How did the stone age culture create such massive monuments, and who were the people archaeologists call "the Olmecs?" To find out, I'll search the slopes of an ancient volcano-- This is black gold, huh? HUNTER ELLIS (VOICEOVER): --and look for clues deep within a bubbling tar pit. I'll lift 20-ton boulders-- I didn't kill anybody or destroy anything. HUNTER ELLIS (VOICEOVER): --and probe the mystery of a primitive people who took on the impossible and won. We're digging for truth, and going to extremes to do it. [music playing] Deep in the Central American jungle lies a mystery that has been puzzling archaeologists for decades-- colossal stone heads. Hi, I'm Hunter Ellis. This monolith is over 30 centuries old and weighs more than 10 tons. But who made it, and how? I've traveled to the heart of Mexico to find out the secrets of the kings of the stone age. They were the Olmecs, the people of the forest. To find them, we have to journey back through the civilizations that have come and gone in this land. The Aztecs are the most familiar-- 500 years ago, they created a vast empire that covered more than 80,000 square miles. They built great cities, huge temples. They sacrificed thousands to their gods, then fell to the Spanish King conquistadors. The Olmecs came before them. The Maya, too, share the Aztec's renown, and also left a great legacy in stone. They ruled an empire that encompassed 100,000 square miles and more than 20 million people. Their temple walls tell us about the rise and fall of their gods and their kings. But go back further still, centuries before the birth of the Maya and 1,200 years before the birth of Christ, the Olmecs emerged from the lowland jungles of modern Mexico. This was the time of Tutankhamun and Ramses the Great in Egypt. While here in Central America there was only jungle until the Olmecs came. In terms of scale, the Aztec and the Maya civilization border on the epic-- but size isn't everything. The Olmecs may have ruled fewer people, but they were also the first to rule. They are a people shrouded in mystery. The jungle has swallowed almost everything they made. In fact, no one even knew they existed until the first giant heads turned up-- colossal heads, strange and disembodied, 17 of them, so far. The Anthropological Museum of Xalapa, Mexico is home to six-- the largest collection of Olmec colossal heads in the world. For curator Roberto Lunagomez, these heads are his museum's greatest mystery. Hola, Roberto. - How are you? - Como esta? - [inaudible] Very good. Thank you very much. Being that it was that long ago, how did they create these heads? What were their tools like? No metal tools. So this is all stone on stone? Only stones against stones, rock against rock. HUNTER ELLIS (VOICEOVER): Roberto says its features were painstakingly carved by grinding and pounding. Who were these people, and what do these huge heads mean? As works of art, the heads are incredible. The largest weighs over 20 tons and stands over 11 feet tall. Every head wears a unique helmet, and every face is an individual-- stern, benign, powerful. As archaeological discoveries go, they're baffling. To find out more, I'm heading to the Olmec's first capital city, San Lorenzo. In their time, this was a swampy jungle. It's the worst place for archaeologists trying to find the remains of an ancient civilization. Human bones, textiles, wood, everything that's not made of stone or pottery, simply rots away. Nothing like hiking through a jungle in 100% humidity. HUNTER ELLIS (VOICEOVER): The first great population center in Central America lived at the top of this ridge. The Olmecs went on to build other cities in this region, but this is where it all began. This is San Lorenzo, what some believe was the first city in Central America. I know, I'm trying to find it, too. HUNTER ELLIS (VOICEOVER): It's hard to see the remains of a civilization here. Unlike Maya or Aztec ruins, all the Olmec's monuments have sunk deep into the soft jungle soil. 3,200 years ago, this ridge was surrounded by dense jungles, swamps and rivers. Even today it looks like an unpromising place to launch the first civilization in Central America. Just don't tell that to Dr. Ann Cyphers-- she's been digging at San Lorenzo for more than 20 years, and has a lot of respect for the Olmecs. ANN CYPHER: What you're looking at is a site that's probably seven square kilometers in size. HUNTER ELLIS: How many people are we talking about? I mean, I look out and it's a huge plateau. On the San Lorenzo site itself, probably about 5,500 people. And of all the projects that have been here in the last 50-60 years, we probably haven't even scratched 1% of the surface-- or the subsurface. So there could be other colossal heads all around us that we haven't-- [interposing voices] There could be incredible things, but since I'm going to have to dig in the dirt to find it out, it's going to take me a lot longer. HUNTER ELLIS (VOICEOVER): So far, San Lorenzo has yielded 10 monolithic heads, but they weren't easy to find. The first heads were excavated in the 1800s. They were met with astonishment. Recovered from deep within the soil, nothing like them had ever been seen before. People were mystified. Speculation was rife. Why did they look so different? Had colonists from Africa carved them? Were the work of survivors from Atlantis? But by the 1940s, archaeologists had gotten over their shock. They began to appreciate them as indigenous works of art, and started calling the Olmecs of San Lorenzo the "mother culture of Central America." It's a story Anne Cyphers knows better than anyone. Over here to the east there's something very, very interesting. OK. ANN CYPHER: Unfortunately, this very, very interesting thing is no longer here. HUNTER ELLIS: It's a huge hole. It's a huge hole and it had something quite colossal in it. HUNTER ELLIS: Ah, a colossal head, I'm guessing. You're so right. Now, which colossal head came from this site? Colossal head number eight was removed from this place. Now that's the beautiful one in front of the museum, right? That's right, as you go into the Xalapa Museum, that is the first head you see and it came from there. Unbelievable. But what's even more fascinating about where it came from is the fact that it was buried, intentionally buried within an earthen platform. In other words, that means it was hidden. HUNTER ELLIS: So you couldn't see it. It was placed on the ground and then the platform was built over it, so that it was completely encased in dirt and so it was totally invisible to people. So it was like a memorial, in a sense. Exactly like a memorial. Something with high degree of symbolism. And interestingly, it's on the east-- the east, the sunrise, the place of the ancestors perhaps. HUNTER ELLIS (VOICEOVER): Amazingly, it wasn't the passage of time that concealed it. This colossal carving was deliberately and ceremoniously buried. All the other heads show signs of weathering and erosion, but not this one. It's unique-- a singular Olmec mystery. But even if their giant monuments can be uncovered, their daily life remains a puzzle-- one that archaeologist Carl Wendt wants to solve. He studies the materials the Olmecs had on hand and how they used them. He says the Olmecs had one signature resource that I need to see for myself. All right, so what do we need? - Buckets. - OK. Let's take some shovels-- HUNTER ELLIS (VOICEOVER): And it looks like he has something messy in mind. That's about it. And your-- you got your boots. Boots? How come there's only one pair? Is this the new guy thing? Yeah. I guess I'm getting dirty. Ah! HUNTER ELLIS (VOICEOVER): We walk into the nearby field. When the Olmecs came here, they didn't hike through farmland, they hacked through jungle. Whatever was here was valuable, and it still is. HUNTER ELLIS: Check this out. Whoa. HUNTER ELLIS (VOICEOVER): It's a lake full of tar. This is awesome. Black gold, huh? CARL WENDT: Yeah, this is the stuff. I can see it bubbling to the surface right over there. That is so cool. CARL WENDT: More or less it's, it's crude oil, you know, it's the stuff that just kind of oozes from the ground. Just go ahead. HUNTER ELLIS: This isn't like ice where you're going to break through at any moment, is it? No. This is-- just be careful though and you don't lose your footing, because I left the rope in the car. So is this flammable? CARL WENDT: You know, it is, but you have to-- I've found in my experiments we have to get this at a pretty high temperature before it actually starts to burn. HUNTER ELLIS: So we're safe for now. We're safe for now, but if you lit a fire and threw this on the fire, yeah, it'll burn. HUNTER ELLIS (VOICEOVER): Carl says the whole region is dotted with seepages like this, surrounding the Olmec's site at San Lorenzo. OK, so how do I want to do this? HUNTER ELLIS (VOICEOVER): This is the heart of modern Mexico's oil country. Here, the crude oil just wells up to the surface and congeals. CARL WENDT: --sample of the water roll off a little bit. There you go. HUNTER ELLIS: Oh, look at that beautiful sludge. You can see the water just bead right in front. Yep. Oh, wow. How many different ways could they have used this? You know, we know they used it for decoration, for example, on figurines and things like this, as a paint. We know they've used it for adhesive. You know, all sorts of different, kind of multipurpose material, I mean, just as people today would use it. It's the glue, it's-- HUNTER ELLIS: It's their duct tape. - It's their duct tape. - A million years [inaudible]. That's it. HUNTER ELLIS (VOICEOVER): It turns out that people have been using asphalt for millennia, especially here in Central America. For Carl, fragments of asphalt found far from San Lorenzo are invaluable. These chunks were once collected and processed by the Olmecs. Most of their artifacts rotted away a long time ago, but a whole range of Olmec materials, primarily wood and textiles, have left impressions in asphalt. That shadowy presence provides an insight into Olmec daily life. So tell me what you're able to learn about the Olmecs by studying a site like this. Well you know, one of the things that I've been doing as part of my work is not only am I trying to do experiments to see how they processed the material, but I have been doing some research on trying to source analyze the material. In other words, trying to-- we have the artifacts from the excavations, and I've been able to trace back some of the artifacts, the asphalt artifacts, to particular areas where seeps are from. And that tells us about trade patterns, exchange, interaction-- all these types of things that are really difficult for archaeologists to understand. HUNTER ELLIS (VOICEOVER): From studying artifacts like asphalt, archaeologists are getting a clearer picture of how the Olmecs traded their raw materials and finished products. They've discovered that the Olmecs traded goods over hundreds, if not thousands, of miles. Well, it looks like we got our two buckets. Is that enough? I think so, and I'm already dirty. All right, well, I'm stuck, so let's, uh, let's unstick our way out of here. All right, that sounds good. HUNTER ELLIS (VOICEOVER): The Olmecs were a small civilization with big ideas. They created huge stone monuments, but their culture remains one of Central America's greatest mysteries. Many of their secrets are still buried in the remains of their first city, a place that archaeologists call San Lorenzo. That can be picked up. HUNTER ELLIS (VOICEOVER): Ann Cyphers is piecing together what this settlement looked like. She does it by taking soil core samples throughout the 30 square mile site. - This is Don Juan-- - Don Juan, Hunter. --and this is [inaudible] who is an archaeologist. HUNTER ELLIS: Ah, Don Juan, [inaudible] very nice to meet you. HUNTER ELLIS (VOICEOVER): Ann says I should give it a try for myself. Her team has done 3,000 core samples at San Lorenzo, evenly spaced every 65 feet across the entire site. Tell me about what you'll find here to indicate Olmec presence. ANN CYPHER: Well, what is very interesting is when you start seeing possible vestiges of structures. For example, floors will leave a specific signature, and so that can be picked up within the dirt. Tell me the difference you'll see. Like, how can you tell if you hit a structure? What is the change that you notice? Well, usually it's house floors. You can find the kind that are made of a blood red sand plaster or an orange sand plaster, or there are then stone pavements, and the core bucket will just bite right through it. And as you pull the dirt out, it's very clear to see that you have gone through a floor. So that red will stand out, the bentonite will stand out, and then you know that at that depth you have a structure? That's right, and you need to measure and find out how deep you have gone with your bucket. OK, so each sample you take, you'll measure the depth so you know what you found where. OK, we're looking at about 31 centimeters or so. No, not about or so-- HUNTER ELLIS: OK. - We want an exact-- HUNTER ELLIS: Very precise. - --measurement. OK, very precise. I'll go right back in here. OK. 31 centimeters. Very good, Hunter. This is about five and a half feet tall here, so what happens when I'm running out of room? Well, when you get down to having the whole extension within the ground, then it will be time for you to add on an extension. And we have more extensions right here. Manually, we've gone down to about 18, 19 meters. - No kidding? - No kidding. That looks like 60 feet. You do that by hand? Do it by hand. Don Juan, muy fuerte. ANN CYPHER: Oh, you need four or five, sometimes six men to be able to do that. HUNTER ELLIS: No kidding? HUNTER ELLIS (VOICEOVER): Now I see why we know so few details about the Olmecs. Their occupation layer is up to 60 feet down. It's like looking for buried treasure. This is an Olmec site, so the treasure I'd like to strike isn't gold or jewels, it's stone-- and it's almost as rare. In fact, the closest source of stone for the Olmec's colossal heads is a long, hard way from here in a place called the Tuxtla Mountains. The Tuxtlas are a group of volcanoes in Southern Veracruz. There are at least 40 miles away from San Lorenzo. Up here, mammoth stones are everywhere. Many of them are bobs-- blobs of lava that are thrown out by an eruption. But if this is where the Olmecs came to get the stones for their monuments, just how did they get them back? The Olmecs didn't select just any type of rock to make their colossal monuments, they used especially hard basalt. I've heard there's evidence of an Olmec workshop nearby. To figure out why the Olmecs chose such a labor intensive medium, I'm meeting archaeologist Dr. Richard Diehl. Great to see you. RICHARD DIEHL: I don't want to get you with a machete. HUNTER ELLIS: Yeah, I appreciate that. HUNTER ELLIS (VOICEOVER): These two roughly shaped rocks betray hours of Olmec labor. Yes, vesicular basalt is what we call it. Comes from the mountain [inaudible] just behind us. HUNTER ELLIS: Does this have a carved head anywhere, or did they get that far? - No, they didn't. What I'm sitting on here would have been the top-- OK. --and they had the sides pretty well smoothed down. And then this tab-- Yeah, I was wondering what that is. Well, we don't know. I suspect that that was left on purposefully at this point in the manufacture to help move it. That is, it may have been a tie down or something. Something that they could actually hold on to, attach something to. It seems to make sense. RICHARD DIEHL: I mean, this is a stone and a means to manufacture. That's what really neat about it. Right. It's not that it's particularly beautiful, because man, it isn't. But it shows you some of the process of manufacturing. HUNTER ELLIS (VOICEOVER): Archaeologists found this stone in two pieces, but by lining up the sculptor's marks, they can see how the smaller slab once rested on the base. Why this type of stone? What was so special about this stone for the Olmecs? Well, I think it was the stone's association with volcanoes. And so it's born in fire. And so I think it had those connotations of the underworld, the abode of the gods under the volcanoes. And this stuff, these boulders all through these fields, were part of volcanic eruptions that I think were then eroded down slope. And we're pretty well at the bottom of the slope here, so this is where they stayed and this is where the Olmecs came looking for the kinds of stone that they wanted to use. I think what they were doing here-- HUNTER ELLIS (VOICEOVER): Richard tells me that a group of master carvers and apprentices might locate a good stone and work on it for weeks. They roughed out the basic shape on site, then they would transport it to San Lorenzo for finishing. And apparently they got fairly well on with working this thing when something happened. Was this an apprentice error, because-- Well, I wonder-- yeah. Because it's broken. After he broke it, he was probably now no longer an apprentice, he was probably a farmer. I think they were a relatively small group of carvers here at any one time, but then when it came time to move the stone, that's when you had to bring in a bazillion people. It could be that the entire community showed up here to help. That's absolutely incredible. It's really amazing what these folks could do. HUNTER ELLIS (VOICEOVER): The stone monuments ended up nearly 40 miles away. How could a stone age culture move rocks weighing up to 40 tons, and why did they bother? It's time for some experimental archaeology. What does it take to move a colossal head? Before the dawn of the Olmecs, the peoples of Central America lived in small groups. They survived by hunting and gathering and small scale agriculture. Populations were sparse. There were no leaders with huge labor forces under their command. Then, in 1200 B.C., the Olmecs emerged from the jungle and established Central America's first political center, a city filled with powerful monuments. What exactly sparked this dramatic development? We may never know, but they left us some pretty large clues-- hefty ones, too. And carving them was only half the battle. How did they move these massive rocks to their capital, which was in the middle of a swamp and 40 miles away? Today, it's a piece of cake. All it takes is a phone call. Let's pick one up and get a sense of the size we're talking about here. Now this is a good rock for a colossal head. Hasta roca, por favor. So this crane is rated to 20 tons, which should be enough to hopefully pick up this colossal rock. Guess we'll see how well these straps hold. HUNTER ELLIS (VOICEOVER): The crane shouldn't have any trouble with this rock, but I'm not so sure about using a single nylon strap. Success. Now we just need to figure out whose head we're going to carve. HUNTER ELLIS (VOICEOVER): 14 tons, no sweat-- and we didn't even lift a finger. All right, let's see if I can swing it around a little bit. OK, so this-- which way? This, this has to go down? This? This? Whoop. The translation thing's a little difficult. HUNTER ELLIS (VOICEOVER): The Olmecs didn't have it so easy. This is about average for the rocks they were moving. Some were more than twice as big. All right, I didn't kill anybody or destroy anything. I think that was lucky. HUNTER ELLIS (VOICEOVER): With little more than brute force and sheer determination, they moved rocks weighing up to 40 tons. But how did they do it? No one really knows, other than it required a lot of manpower. Still, Dr. Carl Wendt has some ideas. It's definitely not an Olmec head. No. it's not an Olmec head, but I think you'd be surprised. Yeah. Let's see. Ah, yeah. So how much do you think each one of these weighs? You know, I'm guessing probably around a half a ton. OK, so about 1,000 pounds. And so some of the smaller Olmec heads weighed how much? Much more, you know, seven, eight tons. OK, so I mean, we're talking about, like, 14 to 20 times this size, basically. Sure. But we're starting small. I'd like to see what we can do on our own here first. All right. All right, well OK. HUNTER ELLIS (VOICEOVER): Might seem a little bit crazy, but when you stop to think about it, what tools did the Olmecs have? They didn't have metal tools, but maybe they had ropes braided from Liana vines, or wooden levers. And a little leverage can go a long way. What did other cultures do? Well you know, that's a good point, because, you know, one of the ways we get ideas about how the Olmec moved it is by looking at other cultures. Other cultures used a number of different devices just to actually reduce again the friction, and ease the pulling of these stones. HUNTER ELLIS (VOICEOVER): Just as the Egyptians deployed mass labor to move the building blocks of the pyramids, so did the Olmecs-- but on a very different scale. San Lorenzo's population was a mere 5,500 people, so their challenge was a bit like Carl's and mine. All right, where do we start? Well, we got the guys, so-- Yeah, I think we can move a lot of rocks with these guys. HUNTER ELLIS (VOICEOVER): We've asked them to figure out how to move this stone using only rope, levers and sweat. I mean, the amazing thing is that, look how many guys it's taking to move these small rocks. Yeah. I mean, I'm just picturing just hundreds of Olmecs now, trying to move stones 10 times this size. CARL WENDT: That's one thing, you know, there's been estimates done that one man, you know, say, could probably move about 50 pounds over a long distance, and say maybe about 100 pounds over a short distance. So that's sort of how we did some of the calculations. HUNTER ELLIS (VOICEOVER): Extrapolating from what one person can accomplish, archaeologists have calculated that more than 1,000 men might have been needed to drag a stone that weighed 40 tons-- that's a couple of full garbage trucks. The move might have taken place in stages that lasted well over a year. We got about 17 guys moving this rock. Sliding it. HUNTER ELLIS (VOICEOVER): The Olmecs probably needed as many people again to feed them, prepare shelters and clear the road. They're moving it, but kind of slow. So I think we should change our techniques a little bit and put it on some sort of a sledge. HUNTER ELLIS (VOICEOVER): Carl says they would have tried to reduce the friction as much as possible, and a wooden sledge does make the pulling easier. - This moves pretty smoothly. - Yeah, a lot better. Yeah. HUNTER ELLIS (VOICEOVER): And remember, they never invented the wheel. The best they might do was to use some logs as rollers. HUNTER ELLIS: Oh yeah, once it gets up on those. HUNTER ELLIS (VOICEOVER): I'm beginning to get a true appreciation of all the obstacles the Olmecs were up against. But the really big invention of the Olmecs was in their organization of human labor. Even using all the materials the Olmecs had available to them, moving a stone like this in this environment is a tough job. What's even more mysterious is what they did when they arrived at the swamps and rivers, because around here they're everywhere. In order to get the stone to their city, which used to reside on that plateau right over there, the Olmecs had to traverse miles and miles of swamp and jungle, which today have been replaced by crops. But in wet season when it rains, this place is entirely flooded and San Lorenzo becomes a virtual island. The population of San Lorenzo was nourished by the rich wetland environment. HUNTER ELLIS (VOICEOVER): Large scale public monuments only became possible because individuals created surplus food, freeing up others to serve as artisans. Even today, one man with a net can gather a lot of food. I want to see how, so I thought I'd meet up with one of the locals to see if he could show me the ancient art of net casting. [speaking spanish] This is going to be really interesting, because my Spanish is horrible. So curl it up. HUNTER ELLIS (VOICEOVER): The Olmecs probably fished pretty much the same, but I bet there were a lot better at it. This is really complicated. I have no idea where any of this is going. HUNTER ELLIS (VOICEOVER): Though their nets have rotted away, ceramic beads have been found that may have been weights for nets like this. Ah! Beginner's luck! My first fish. Ha! HUNTER ELLIS (VOICEOVER): The water was a rich resource, but it set limits on the Olmec's living space. Still, they had a solution to that problem, and the manpower to make it happen. Archaeologist Ann Cyphers tells me, despite the relatively small population, they transformed their landscape. We're talking about millions and millions of cubic meters of fill that were brought in to create more space for habitation. The whole site was ringed by these artificially built terraces. And the amount, the volume-- we're talking about millions and millions and millions of cubic meters of dirt. So they put a lot of hard work into developing this site? Yeah. And that also indicates the amount-- in an indirect way-- the amount of labor necessary. We're talking about a lot of labor. Even though we're talking about centuries of development, it's still a lot of manpower. - Right. So you're thinking the masses were probably the labor force, and there's a very few leaders that would sort of delegate the work? It required leadership. Exactly. HUNTER ELLIS (VOICEOVER): The early Olmecs chose natural high ground to live on for easy access to the productive wetlands. Then as their population grew, they added terraces and expanded the high ground until the plateau encompassed more than one million square yards. These were public works projects on a scale never before seen in Mesoamerica, and they required having someone in charge. Who were these leaders? The colossal heads may be the key to that mystery. In fact, archaeologists believe they each portray, not the face of a god, but the likeness of a king. I remember Roberto showed me something. Several of the heads bear strange marks. Do these traces indicate that there was something else here before the head was made? The answer was only recently discovered, and it adds a totally new dimension to our knowledge of the heads. These shapes are reminiscent of shapes on a large sculpture called a royal platform, or throne. The arches behind this kneeling figure form deep niches that turn out to be an exact match. This discovery means that a royal throne was tipped up on end and to face was carved into its smooth top. So this over here was the top of the old throne. So maybe that is why we're seeing a much more flat face, right? Exactly. HUNTER ELLIS (VOICEOVER): It may be that basalt boulders had proven so difficult to transport that the Olmecs were systematically reusing them. You might even call it stone age recycling. One theory is that an incoming ruler could create his own likeness out of his predecessor's throne, another is that an inauguration throne could be used to create a likeness upon a ruler's death. We just don't know. One thing's for sure, these huge stones were important symbols of a ruler's power and his ability to command hundreds of people. The Olmecs were masters at exploiting everything in their environment, and they had the manpower to think big. Using sledges or rollers and brute force, they pulled their massive rocks from the mountains. But when they reached the rivers and wetlands, it was time for a very different tactic. I'm meeting up again with Carl Wendt to test some of his theories of what the Olmecs did next. Hey, Carl. How's it going? How you doing? Looks like everybody's hard at work here. Yeah, yeah, we're doing some experiments. We're trying to get an idea of how the Olmecs moved their stone. The thing is, we don't really know, and that's one of the main problems. One of the ideas that I have is that they might have actually transported it for some period of time on water. Well, can you show me what you guys are doing then? CARL WENDT: Yeah. HUNTER ELLIS (VOICEOVER): The Olmecs must have been expert boat builders. Daily life in this region would have required a variety of vessels for both fishing and transportation. But did they have a boat that could carry a rock weighing 40 tons? Carl doesn't know what any of their boats actually looked like-- none have survived. But he does know they had access to a material that would have helped a lot. It's the same stuff I helped him collect, the bitumen-- natural asphalt. We find the asphalt artifacts in our excavations, and especially at sites near rivers there's a lot more of the asphalt. One of my ideas is that they used it primarily to seal watercraft. Interesting. So it waterproofs your vessel? Exactly. HUNTER ELLIS: So tell me about the process. Well, what we'll do is we're going to put it in the asphalt into the pot. We'll cook it down for some time to evaporate the more volatile components, and then at which time, maybe after 20 minutes or so, we'll add some of the additives and be ready to go. And is this how the Olmecs would have done it? You know, it is, because in our excavations we find pots with residues of asphalt on the interiors, and then drip marks actually on some of the exteriors, suggesting that they would've heated it in pots, processed it, and then poured it out, you know, for application-- - All right. - --just as we're going to do. - So let's get cookin'. Let's do it. So we're gonna pour this in there, right? Yeah. HUNTER ELLIS (VOICEOVER): This recipe is more complicated than it looks. Carl says he threw out hundreds of batches that were too runny, too sticky, or too brittle to use. CARL WENDT: I threw it away. [interposing voices] - There we go. - Good stuff. All right. Well, go ahead and put it on fire. And then how long does this have to heat for? You know, we'll probably heat this for about maybe 20 minutes or so, and then we can take some out and we'll actually test it and see how it's turning, how it's changing. HUNTER ELLIS (VOICEOVER): Cooking changes the tar's chemical bonds, transforming it into a pliable substance that dries strong. And so this is starting to thicken the mixture. I can kind of feel it change from that area of whipped cream to almost like yogurt? Yeah, it's going to start changing a little bit, and what we're going to do is we're going to cook it for just a little bit longer so it really fuses with the other material. HUNTER ELLIS: It's starting to bubble around the sides. And what's going to happen is that it's going to probably just about double in size. - OK. And if we don't watch it, what's going to happen is it's going to overflow, hit the fire, and we'll have a fireball. HUNTER ELLIS (VOICEOVER): Unfortunately, our lawyers say no fireballs. Maybe next time. CARL WENDT: The next step is waiting for a little bit till we can cook off some of the water that, you know, when we collected it, it was kind of in there. And then what we'll do is we'll add our additive, which is this leaf. This is oha Blanca. HUNTER ELLIS: But does it thicken the mixture? Is that how it works? - It does. So that, you know, the asphalt doesn't melt in the sun. Well, I'm melting in the sun right now. This is a hot business. Woo! CARL WENDT: Yes, indeed. HUNTER ELLIS (VOICEOVER): The Olmecs used any leaf that was handy, or sometimes sand or dirt. Adding other materials to the mixture while it's cooking reduces the time it takes to thicken, and the amount of wood needed to fuel the fire. There's little difference between the asphalt the Olmecs made 3,000 years ago and the stuff we pour on our roads today. So what type of design are you using? I mean, what kind of canoe could the Olmecs have had? CARL WENDT: Well, since everything rots here, we really don't have any idea if they had plank canoes like this. HUNTER ELLIS (VOICEOVER): Carl explains that the Olmecs probably had rafts or dug out canoes. Today large trees are hard to come by, so he's experimenting with different ways of building them. Beautiful. All right. CARL WENDT: You know, they would have still had to seal the canoes in some way, or the watercraft in some sort of a way. HUNTER ELLIS (VOICEOVER): Let's try out our asphalt. This is the same way they would have done it, too, huh? Yep. HUNTER ELLIS (VOICEOVER): We're using it to make our boat watertight. The Olmecs could have made plank canoes, too. Carl has found asphalt with the impression of Royal Palm wood, a tall, straight tree that splits easily. Even if the dugouts were their only canoes, they may have been painted with asphalt to make them resistant to rot. Now, how long does this take to harden? The mixture we have right now is going to harden pretty quick but, you know, we need some time to let it sit and dry. No, that's really good. Nice stuff, huh? By the way, so what works well with this? - Baby oil. - Really? Or diesel for the really adventurous types. Hopefully we can clean up. HUNTER ELLIS (VOICEOVER): This doesn't look much like a stone age boat, but it works for our purposes. Will our Olmec boat carry its load, or will we be swimming with the caymans? 3,000 years ago, the Olmecs were moving 40 ton blocks of stone over miles and miles of swamps and rivers, and they would have needed watercraft big enough to float a giant rock. We don't know what these boats looked like, but we do have an idea of their size. [speaking spanish] HUNTER ELLIS (VOICEOVER): Archaeologist Carl Wendt and I built a canoe using the same asphalt recipe that the Olmecs used 3,000 years ago. Will it seal our boat well enough to float a rock? We're at the Chiquito River near San Lorenzo. Rivers snake all through this region. A water route might have meandered, but it would have been a lot more efficient than dragging over land. Archaeologists have even suggested that the Olmecs floated their rocks into the Gulf of Mexico and then up the [inaudible] River. First I just want to see if this thing leaks. So far, so good. It's waterproofed, huh? - Right. How do you feel about putting a big stone in here? Oh, I don't know if that's a good idea yet. I think if we put the stone in, you'll have to go by yourself. HUNTER ELLIS (VOICEOVER): This is about the size of a small utility vessel, but the Olmecs may have had canoes up to 50 feet long for their trade routes. Still, floating a 20 ton rock would require an even bigger boat than that. Our small canoe can't even support this relatively small stone. We need a lot more buoyancy. I think what we'll have to do is we'll put a couple of these together, you know, lash them somehow. OK. We'll get some rope and then we can maybe get some sort of a platform built. And that'll spread the weight out over a greater area there. I think so. Yeah, because I don't think we're going to do anything with this. - No, this is a little unstable. By itself, right. All right, some work to be done. Let's get to work. - Let's do it. Yeah, check this out. Now this is a boat. CARL WENDT: Yep. Man, this is sturdy. They did a nice job. Yeah, yeah, it is [inaudible]. Now, how many people can they put inside of each of these canoes? I'd say probably safely around five, six maybe. OK, so that's roughly, you know, we're dealing with about 750 each, and just over 2,200 pounds or so. Think we can move a big stone this way? You know, to tell you the truth, this feels pretty solid. I'm pretty optimistic. - Should we put it to the test? - Let's do it. - All right. - OK. - Let's do it. [speaking spanish] This is where we turn it over to the experts. What's happening now is what happens all over the world-- everybody has an opinion on how it should be done, so they're sorting it all out and we'll see the results. Unbelievable. Oh my gosh. Can you imagine a stone 20 times that size? Woo hoo! HUNTER ELLIS (VOICEOVER): Our calculations were close to dead on, but we're a little unbalanced. Between the stone and three guys, we're on the verge of taking on water. But the Olmecs knew what they were doing. Once we load the stone onto the raft, it not only moves along easily, it also requires a much smaller team. Now the number crunching can begin. Our half ton stone required three 15-foot canoes. A stone 80 times this size would need 240 of these canoes lashed together. But if the Olmecs had 50-foot dug out canoes with a capacity of three tons, then they'd only need 14 boats. That's a little bit easier to picture. It would utterly dwarf our boat. 3,000 years ago, the Olmecs brought their colossal rocks down from the volcano. Their rulers were the first to organize and inspire a population to attempt gargantuan public monuments that would project their newfound power. They created the first great civilization in Mesoamerica, one that influenced the Maya and the peoples who came after. The colossal heads are artifacts the likes of which had never been seen before, or since. Even today, they're all that many of us know of the Olmecs, the immortal ambassadors of the kings of the stone age.