Copahue (Spanish pronunciation: [koˈpawe]) is a stratovolcano nestled on the border between Argentina and Chile. There are nine volcanic craters along a 2 km (1.2 mi) line, and the eastern summit crater contains a briny, acidic 300 m (1000 ft) wide crater lake. Twentieth-century eruptions from the crater lake have ejected pyroclastic rocks and chilled liquid sulfur fragments. Copahue means "sulphur waters" in Mapuche.[2]