Irruputuncu, Stratovolcano on the Chile–Bolivia border, Tarapacá Region, Chile

Irruputuncu is an active stratovolcano rising to around 5,160 meters in the Central Andes of Chile. The mountain features two separate summit craters that mark its volcanic nature.

The volcano demonstrated active behavior in November 1995 when phreatic eruptions produced a dark plume rising above the summit. This event confirmed that the mountain remains geologically active today.

The name Irruputuncu comes from Aymara: iru, the spiny Peruvian feather grass, and phutunqu, a small clay vessel, hole or crater. Alternative spellings in use are Irruputunco and Iruputuncu. The volcano stands on the Bolivia–Chile border, in San Pedro de Quemes municipality, Nor Lípez Province, Potosí Department, and in Pica commune, Tamarugal Province, Tarapacá Region.

Visitors need substantial physical preparation and high-altitude acclimatization before attempting a visit to this remote location. The mountain is far from towns, so careful planning and proper equipment are essential for any exploration.

The active crater is the southwestern one, 200 m wide; the summit's other crater, Crater II, is the youngest and fed seven short lava flows and lava domes. Fumaroles release 21–50 tonnes of sulfur dioxide a day, leaving sulfur deposits in the crater.