Pozo de las Ánimas, Natural sinkhole formation in Malargüe Department, Argentina

Pozo de las Ánimas is a doline with two large sinkholes separated by a thin rock wall. The northern crater contains a light blue lake at its bottom, while the southern depression has gentler slopes covered with sparse plants.

The two depressions are dolines formed by groundwater dissolving underground gypsum beds, causing the ground to subside and collapse. In 1981 a team led by Rodolfo Rogelio Rocha measured the craters at about 200 m across, 80 m down to the lake and 20 m below the water. Erosion is expected to join the two wells into one.

The name comes from an indigenous legend: a group fleeing pursuers heard moans at night and found their enemies trapped in two collapsed pits, drowned. They called the site "the place where the souls cry", and the name Pozo de las Ánimas keeps that story.

The two craters can be viewed from various vantage points, but safe viewing areas are located on the stable rim edges around the formations. Wear sturdy footwear and avoid areas where the ground becomes unstable or drops off steeply.

The two depressions are separated by a narrow rock partition that erosion is expected to breach, eventually merging them into a single well. Their dimensions were measured in 1981 by a team led by Rodolfo Rogelio Rocha: about 200 m across, 80 m down to the lake and a further 20 m below the water.