Nevado Sajama ([neˈβaðo saˈxama]; Aymara: Chak Xaña) is an extinct stratovolcano and the highest peak in Bolivia. The mountain is located in Sajama Province, in Oruro Department. It is situated in Sajama National Park and is a composite volcano consisting of a stratovolcano on top of several lava domes. It is not clear when it erupted last but it may have been during the Pleistocene or Holocene. The mountain is covered by an ice cap, and Polylepis tarapacana trees occur up to 5,000 metres (16,000 ft) elevation.