centuries before the birth of Christ the ancient Maya are a rural civilization they grow most of their food and one crop is all-important corn to successfully cultivate corn and their other crops the Maya need to mark the changing seasons in a tropical climate where daylight doesn't vary much between summer and winter this is not so easy [Music] but already the Maya are developing knowledge that will enable them to accurately track the seasons in the southwest corner of the ancient city of Tikal stands one of the Maya's oldest sacred sites around 600 BC the Maya started work on this complex of buildings almost covered by dense jungle today the site is known as mundo perdido the lost world [Music] but for the ancient Maya it served a very visible purpose several times a year the Maya climbed mundo perdido central pyramid to observe the sky to the east from this vantage they could see three small structures known today as e1 e2 and e3 viewed from the pyramid during the summer solstice the Sun ascends from behind structure e 1 during the equinoxes it rises from behind the central pyramid e 2 and during the winter solstice it emerges from behind III [Music] in the land of the Maya the winter solstice for shadows a time of dryness while the summer solstice heralds heavy rain sites like mundo perdido give accurate knowledge of when a dry or rainy period is at hand for the Maya using astronomy to mark the seasons is not an agricultural technique it is the essence of religion [Music] you