Laguna Lejía is a salt lake located in the Altiplano of the Antofagasta Region of northern Chile. The landscape of the area is dominated by the volcanoes Chiliques, Lascar, Aguas Calientes and Acamarachi. It is shallow and has no outlet, covering a surface area of about 1.9 square kilometres.
The lake basin is surrounded by volcanoes, such as Aguas Calientes, Lascar, Tumisa, Lejía, Chiliques and Cordon de Puntas Negras; the lake is endorheic and has a 193 square kilometres (75 sq mi) large catchment, and a lava flow forms its southern shore. High altitude Andean lakes such as Lejía Lake are studied as potential analogues to waterbodies on Mars, given similarities between their present-day environment and the environments of early Mars.