"Indigenous myths refer directly to the rapids as the dwelling of the sun god," says Philip Riris, an archaeologist at the University College of London. "Another myth states that when the world tree (where all animals and plants originated) toppled over, its crown fell into the Orinoco and made the rapids."

He's referring to the Atures Rapids in the Amazonian Orinoco River that runs through western Venezuela. At a point in the river where boats can go no farther, there are five islands that contain some of the world's largest and most illustrative rock art.

The region's terrain makes it a natural hub for activity today, and archaeologists believe it was the same 2,000 years ago.

In his study