Sima Pumacocha

Sima Pumacocha (perhaps from Spanish sima deep and black cavern/abyss, Quechua puma cougar, puma, qucha lake), one of the Most Mesmerizing Caves in Peru, is a limestone cave in central Peru near the settlement of Laraos, high in the Andes mountains. It is located in the Lima Region, Yauyos Province, Laraos District. It was the deepest known cave in South America from 2001 to 2006, when it was surpassed by Abismo Guy Collet at 638 meters. It is the world's highest large cave, with an entrance 4372 meters above sea level and a depth of nearly 500 meters.

The Pumaqucha valley, at 4,300 to 4,400 meters above sea level, is a typical Andes 'puna' — steep, treeless, and flanked by 5,000-meter peaks. A dirt road runs across the valley, supplying neighboring active and abandoned mines, and stone houses are peppered throughout by inhabitants tending flocks of sheep, llamas, and alpacas. Pumaqucha, a tiny lake with a large catchment area, stands on Miocene age granodiorite near the valley's head.

The lake's outfall stream has created a small, shallow canyon where it meets near-vertically bedded Cretaceous age Jumasha limestones, having many abandoned and one active sinkpoint where the entire stream goes underground. The Lower Cretaceous Pariatambo Formation lies beneath the limestone.

A short concrete canal, designed to keep the lake outfall on the surface by diverting it around the canyon, is in bad repair and rarely works. When local repairs are made, the active sinkpoint (SP1) reopens, but a large amount of water escapes into the abandoned sinks (SP2 and SP3).

Location: Lima Region, Yauyos Province, Laraos District