Sótano del Barro

The Sótano del Barro is a colossal sinkhole in the mountains of Arroyo Seco municipality, north of Pinal de Amoles and northwest of Jalpan. It is about 455 meters deep, with a sheer drop of roughly 410 meters, and its mouth measures some 420 meters across at its widest. That makes it one of the deepest open-air pits in the world, and one of the great natural sights of the Sierra Gorda.

Its fame goes beyond its size. The walls of the pit shelter a colony of military macaws, the large green guacamaya verde, one of the most important populations of this endangered parrot in Mexico. The birds leave the pit in the morning and return in the late afternoon, and seeing them circle above the void, calling loudly, is the reason most people make the trip.

The Sótano lies inside the Sierra Gorda Biosphere Reserve, and descending into it is strictly forbidden to protect the macaws. You see it from the rim, which requires a long hike through the forest. It is a full-day outing best done with a local guide, and the reward is a view few travelers ever see.