Caddo Lake (French: Lac Caddo) is a 25,400 acres (10,300 ha) lake and wetland on the border between Texas and Louisiana, in northern Harrison County and southern Marion County in Texas and western Caddo Parish in Louisiana. The lake is named after the Southeastern culture of Native Americans called Caddoans or Caddo, who lived in the area until their expulsion in the 19th century. It is an internationally protected wetland under the RAMSAR treaty and features the largest cypress forest in the world.