Acotango
Acotango is the central and highest of a group of stratovolcanoes straddling the border of Bolivia and Chile. It is high. The group is known as Kimsa Chata and consists of three mountains: Acotango, Umurata () north of it and Capurata () south of it. The group lies along a north–south alignment. The Acotango volcano is heavily eroded, but a lava flow on its northern flank is morphologically young, suggesting Acotango was active in the Holocene. Later research has suggested that lava flow may be of Pleistocene age. Argon-argon dating has yielded ages of 192,000±8,000 and 241,000±27,000 years on dacites from Acotango. Glacial activity has exposed parts of the inner volcano, which is hydrothermally altered. Glacial moraines lie at an altitude of but a present ice cap is only found past of altitude. The volcano is a popular hiking route in the Sajama National Park and Lauca National Park. It is on the border of two provinces: Chilean province of Parinacota and Bolivian province of Sajama. Its slopes are within the administrative boundaries of two cities: Chilean commune of Putre and Bolivian commune of Turco. To climb the summit from the Chilean side is dangerous due to land mines, however