La Venta and the Tatacoa badlands

The richest Neogene fossil assemblage in South America outside Argentina, in the Honda Group of Tolima and Huila in Colombia, and the ground that gives the Laventan age its name. The animals lived between about 13.8 and 12 million years ago, before the Great American Interchange brought northern animals down the isthmus, so the fauna is the old South American one: monkeys, enormous caimans, terror birds, and river fish whose families still swim in the Amazon. The climate then was far wetter than the dry forest that stands there now. The badlands above it are the Tatacoa, 330 square kilometres of ochre and grey gullies that Gonzalo Jimenez de Quesada called the valley of sorrows in 1538, and which are visited today as much for the night sky as the rock.