Aracar is a large conical stratovolcano

Stratovolcano

A stratovolcano, also known as a composite volcano, is a tall, conical volcano built up by many layers of hardened lava, tephra, pumice, and volcanic ash. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile and periodic, explosive eruptions...

 in northwestern Argentina

Argentina

Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...

, just east of the Chile

Chile

Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...

an border. It has an uneroded summit crater about 1.5 km (0.93205910497471 mi) in diameter which contains a small crater lake

Crater lake

A crater lake is a lake that forms in a volcanic crater or caldera, such as a maar; less commonly and with lower association to the term a lake may form in an impact crater caused by a meteorite. Sometimes lakes which form inside calderas are called caldera lakes, but often this distinction is not...

. It is located on the edge of the Puna de Atacama

Puna de Atacama

The Puna de Atacama or Atacama Plateau is an arid high plateau averaging about above sea level and spanning an area of , in the Andes of northern Chile and Argentina and southwest Bolivia. Before the War of the Pacific , the region belonged to Bolivia. In 1898 it was ceded to Argentina in...

, a high desert plateau east of the Atacama Desert

Atacama Desert

The Atacama Desert is a plateau in South America, covering a strip of land on the Pacific coast, west of the Andes mountains. It is, according to NASA, National Geographic and many other publications, the driest desert in the world...

. The only observed volcanic activity was a possible steam or ash plume on March 28, 1993 seen from the village of Tolar Grande about 50 km (31 mi) southeast of the volcano.