The lowest part of an intermontane basin or bolson, which is frequently flooded by runoff from adjacent highlands or by local rainfall. Sediments consist largely of colloids, clays, and evaporites, e.g. halite, gypsum, and sodium sulphate. The surface is generally flat, with mudflats and locally small dunes. The name (playa is the Spanish word for ‘beach’ and salina for ‘salt-mine’) was first applied to the arid basin-and-range province between the Colorado Plateau and Sierra Nevada, in the western USA, but is now used to describe such areas throughout the world.