The bones of gomphotheres — elephant relatives that lived in the Americas until the Pleistocene extinctions — of giant ground sloths, of ancient bears and large felines and various other Pleistocene megafauna, accumulated on the floors of these pit chambers.

And at least once, a human being fell in too.

Or was brought there deliberately.

The question of how Naia came to be at the bottom of Hoyo Negro — whether she fell accidentally, was placed there intentionally, or died inside the cave system while exploring it — is one of the questions that the discovery raised and that science has not fully resolved.

Who Naia Was