Tatacoa is a 330-square-kilometre stretch of tropical dry forest that erosion has stripped down to bare, cracked earth, which is why it looks like a desert and carries the name of one. Rain and wind have carved the ground into a maze of gullies, spires, and ravines split into two worlds: the ochre-red badlands of El Cuzco, stained by iron oxide, and the pale grey, crater-like channels of Los Hoyos. Giant columnar cacti stand between them. Beneath the surface lie the La Venta fossil beds, one of the richest records of prehistoric life in South America. They hold 13-million-year-old bones of extinct monkeys, crocodiles and giant turtles, and in 2024 they won the site a place on the international list of geological heritage. The name Tatacoa comes from the rattlesnakes once reported across this ground. The town of Villavieja, reached through Neiva, is the gateway.
By day the heat is fierce and the red walls seem to glow; as the sun drops they soften to copper and the ravines fill with shadow. But Tatacoa's real fame comes after dark. Far from any city light, its dry, near-cloudless air gives it one of the clearest night skies in Colombia — so clear that in 2019 it became the country's first certified Starlight destination. In the dry months the core of the Milky Way arches overhead, bright enough to see with the naked eye, and a roadside observatory turns its telescopes on Saturn's rings and the planets. Walking the gullies happens in near-total silence: there is no traffic, no shade and hardly a plant in sight, only cracked earth underfoot and open sky in every direction.