Far on the eastern side of the African continent, a rugged arrow is piecing into the Indian Ocean. This is the Horn of Africa. Surrounded by the waters of the Red Sea, the Gulf of Aden and the Indian Ocean to the east, as well as Savannah and the Sahel Zone to the west, 145 million people live across these four countries, amidst some of the tallest mountains and most unforgiving desert of the continent. In this video we will have a closer look at the 3 distinct geographical regions of the Horn of Africa, diving into the Ethiopian Highlands, the Red Sea coast along Eritrea and Djibouti and finally the Somalian Desert which wraps around the tip. Chapter 1 - The Ethiopian Highlands Sculptured by the immense forces from the inside of the planet, the Ethiopian highlands are the largest expanse of rugged terrain on the African continent The mountains, volcanoes and gorges are the product of an intense tectonic activity that has shaped eastern Africa for the past 75 million years. Looking at a topographic map of Africa, we can discern several lines through the mountains and great lakes, which showcase the forces of the Great African Rift system, which is currently splitting the African tectonic plate into two, and these processes are also largely responsible for the rugged Ethiopian Highlands. Moving apart at around 6 mm per year, the Somali and Nubian plate are drifting in opposite directions due to an unknown source in Earth's inner mantle. A thin, fragile, and rugged new crust is forming from the volcanic outflows between them, and this process, combined with a separate and more intense local uplift around present-day Ethiopia, has elevated this almost circular highland above the rest of Africa. To this day, the East African Rift keeps expanding and throughout the past couple of million years has created two pronounced subregions across the Ethiopian Highland. The Northwestern section is referred to as the Abyssinian Massif, while its counterpart across the rift is called the Harar Massif. Both regions share many similarities, with high precipitation and several mountains surpassing the 4.000 meter or 13.100 feet mark, but there are also some distinct differences. When it comes to setting records for example, the Abyssinian Massif in the North East outshines the Harar Massife in pretty much every geographical category. It is home to the tallest mountain of Ethiopia with the 4550 meter or 15000 feet tall Ras Dashen, whose meltwater from the regular snowfall drains through the deepest gorge of Ethiopia and then powers the largest hydroelectric power plant of the country. A bit further south in the next drainage basin, we can find the largest lake of Ethiopia, which also contributes the largest tributary to the River Nile. Every wet season between June and August, the monsoon over the Indian Ocean is pouring down on the Ethiopian Highlands, increasing Lake Tana's outflow 50-fold, and seasonally flooding the banks of the River Nile, over 2.000 kilometers or 1200 miles downstream. On the other end of the Abyssinian Massif, just before the Great African Rift has pulled the mountain masses apart, the Ethiopian capital Addis Ababa can be found, which with 5.7 million inhabitants in its metro region constitutes the largest city of the country and the region as a whole. Up until the late 19th century, the city remained a modest resort town, known for its mineral springs, but when Menelik II, the king of Shewa established his Imperial Palace in the lush valley, it quickly attracted merchants and craftsman from all over the country and began its meteoric rise to the most influential city of the country. Just behind the city boundaries of Addis Ababa, the diagonal cut of the Great African Rift penetrates through the Ethiopian Highlands, and has created a landscape of many lakes, forested mountain slopes and canyons in its path. On the other side of the roughly 100 kilometer or 60 mile wide gap, now on the newly formed Somali Tectonic Plate, we are greeted yet again by the vast table mountains and canyons which are stretching in all directions. Across this part of the Highlands, very few pointy summits can be made out and instead, flat plateaus at elevations surpassing 2000 meter or 6600 feet, with steep and narrow gorges are the norm. The landscape of volcanic origin was once a lot more pointy, but millions of years of glaciation have done their work, flattening out the summits and carving deep meltwater outlets in between them. Going back to the Great African Rift which is penetrating the Ethiopian Highland, and following the rift Northwards, the faultline appears to be opening up towards the Red Sea Coast, from where the rift continues into two different directions along the Red Sea and Gulf of Aden. At this junction, the land abruptly drops flat to the sea level, creating one of the most unique and inhospitable landscapes of the planet, and leading us to Chapter 2 - The Afar Triangle At the tri-point intersection of the Nubian, Somali, and Arabian plates, one of the most inhospitable places on Earth has formed, its scorching heat challenging anyone who dares to enter. The Afar Triangle, as this region is known, lies at or below sea level and stretches from central Ethiopia to central Eritrea and across to western Somalia, entirely encompassing the country of Djibouti. This depression is by far the most volcanically active region of the horn and full of peculiar features. Having been spared by the forces of glaciation, many of the volcanic cones remain intact, and are now sticking out of the otherwise flat landscape. Several of these volcanoes are still active today, with 13 of these having erupted in the last 200 years. The most notable of these is the Erta Ale in the north of the triangle, which has continuously erupted for almost 60 years now. The constant lava outflows from Erta Ale regularly overflow, covering the surroundings of the shield volcano with fresh basaltic rock. In the center of the cone, a continuous lava lake has been simmering since the beginning of the 20th century. It is one of only eight exposed lava lakes on the globe and holds the distinction of being the longest-lasting continuous lava lake on the planet. The Erta Ale sits in the middle of Danakil Depression, which is widely regarded to be one of the most inhospitable places on the planet. The seemingly extraterrestrial valley holds the undisputed year round average temperature record at 35°C or 95 degrees Fahrenheit and daytime temperature exceeds 50°C or 122 degrees Fahrenheit on a regular basis, putting places like Death Valley in California to shame. Yet this temperature isn’t even the most challenging aspect of trying to live inside the Danakil Depression. Any water finding its way into the bowl, which lies 125 meter or 410 feet below the sea level, evaporates almost immediately, creating a thick and impenetrable salt crust. At places where water does manage to stay around for a bit, it mixes with the toxic sulphuric and chloride glasses and minerals, byproducts of the heavy volcanic activity, creating highly acidic and colorful ponds, ready to dissolve any organic matter which may enter it. Paradoxically however, it is in this depression, though in a little less hostile section, where archeologists found the most astonishing skeleton. Now nicknamed Lucy, the Australopithecus Afarensis bones have been dated back to 3.3 million years ago, roughly the time of the earliest stone tools which have been found to be made for hominid use, supporting the theory that modern humans may have their origin in this very region. At 125 meters below sea level, the Danakil Depression is already the sixth-lowest point on Earth's surface, but it isn't even the lowest point in the Afar region. That title belongs to Lake Assal, situated about 250 kilometers (150 miles) southeast on the other side of the Afar Depression within Djibouti. Plunging to a depth of 155 meters (509 feet) below sea level, Lake Assal is the lowest point in Africa. Like many other lakes below the sea level, its waters have no outflow, and constant evaporation causes them to become hypersaline. Climbing out of the depression to the east again, we are leaving the 3rd smallest country of continental Africa behind and the 3330 kilometer or 2070 mile long Somali coast starts wrapping around the easternmost point of the continent, bringing us to Chapter 3 - The tip of the Horn Lying in the middle of arguably the politically most unstable region of the planet, the outermost band of the Horn of Africa is an embodiment of the struggles that the region went through in the past 100 years. Just west of the Horn of Africa lies South Sudan, the youngest country to be recognized by the United Nations in 2009, but this title may soon be challenged within the Horn itself. Having gained independence as the State of Somaliland in 1960, after being a British Protectorate for the past 75 years, the state quickly unified with the former Italian Somaliland into a promising young nation, but partisan politics, a communist coup, a failed invasion of Ethiopia, famine and tensions between the underlying clans quickly turned it into a failed state. Since the 1990s now, the northern Somaliland has been trying to gain independence from the South again, but the fight for international recognition to support their claim of the Horn of Africa remains an uphill battle. While international diplomatic relations between Somaliland and the rest of the world are growing, suggesting potential future independence, the state still faces a long and uncertain path. Geographically, the far north is covered by a thin coastal mountain range called the Ogo Mountains, which is still a product of the tectonic rift running along the Gulf of Aden. The forested mountain slopes here are standing in stark contrast to the rather unanimously hot and arid desert which covers virtually the rest of Somalia, until a pocket of arid steppe starts forming, south of Somalia's Capital city Mogadishu. Only small and seasonal rivers are crossing the desert here, which are typically not enough to sustain any form of substantial flora, fauna or agriculture. Nearly everybody in rural Somalia here practices some form of nomadic or semi nomadic pastoralism, relying on sheep, goat and camels for their livelihood, and occasionally collecting some rubber to make ends meet. To find the first lands suitable for basic agriculture, we have to travel over 1000 kilometers further south, where the first permanent rivers are crossing the landscape. Coming down from the Ethiopian Harar Massif, the Shabelle River crosses the Somali Border around half way down and makes its way straight to the Indian Ocean. Elevated land at the coast however, makes the river take a sharp southwards turn before reaching Mogadishu, and transports the waters over 500 kilometers parallel to the Indian Ocean coast. Just before draining into the Ocean, the River tributes to the other major river of the country, the Jubba River, whose drainage basins together spark the the only agriculturally viable land of Somalia. Despite the somewhat fertile soil, occasional rainfall and accessible land, agriculture in Somalia is still one of the technologically least advanced industries in the entire world and many farmers are merely achieving self sustainability. Overall, the violent past, full of civil wars, ethnic clashes, and severe mismanagement, have created unfathomable living conditions, especially in rural Somalia, which give the country the lowest Human Development Index score of any country on the planet. While the harsh climate and politics keep on challenging the Somali population, on the broader picture we can say the geography of the Horn of Africa is a fascinating case study where fertility and barrenness, summits and depths, and prosperity and despair coexist in close proximity on the most eastern tip of the African continent. If you want to learn more about the most southern tip of the African continent, I can recommend this mini documentary, which dives into the geography of South Africa, or watch what YouTube thinks is best for you here. Hope to see you in the next one, cheers.