Laguna de Cotacotani or Quta Qutani is a lake located in the Andean Altiplano of the Parinacota Province, Arica-Parinacota Region, Chile. It lies 4 km northwest of Chungará Lake, which is one of the highest lakes in the world and is surrounded by several volcanoes, such as the Payachata volcanic group, Sajama volcano and Wallatiri.
Cotacotani is separated from the lake Chungará by a strip of volcanic rock and receives groundwater inflow from that lake, however its major sources are Benedicto Morales River and El Encuentro Creek. Cotacotani Lake's main feature is the considerable number of islands and islets that it holds, which are really lava hummocks generated by a past volcanic event. With a surface of 6 km2, the Cotacotani holds a volume of water between 30 and 40 million of m³, which empty through Lauca River into Coipasa Lake, in Bolivia.
Wikipedia https://en.wikipedia.org/wiki/Cotacotani_Lake
Coordinates -18°11'22.377" N -69°13'25.279" E