Fossilised algae and coral deposits in Gruta de las Galaxias cave near Salar de Uyuni, Aguaquiza, Nor Lipez Province, Potosí Department, Bolivia

These unusual formations in the Gruta de Galaxias cave at Aguaquiza (on the southern shore of the Salar de Uyuni) are fossilised algae and other marine plants and deposits, including stromatolites. They date from the time when the Salar and surrounding area were covered by the huge prehistoric Lakes Minchin and Tauca.