Hundreds of Indigenous Mayan people in Guatemala ushered in the new year according to their calendar with a spiritual ceremony at the sacred Mayan site of Kaminaljuyu, in Guatemala City, on Tuesday.

In the Caribbean jungles of Quintana Roo, two Mayan brothers lived. They were fierce warriors. And they are still defending their land, in the forest of present-day Mexico.

Here, we explore six notable civilizations that have collapsed, shedding light on some of the causes behind their demise and ...