Volcán Maipo, Stratovolcano in the Andes Mountains, Chile-Argentina border

Volcán Maipo is a conical stratovolcano rising 5,323 m above sea level on the Argentina-Chile border, built on the Diamante caldera and standing about 1,900 m above its floor. The border crosses the summit, leaving the crater on the Argentine side. Laguna del Diamante lies immediately east of the peak.

The volcano formed in the Pleistocene. A lava flow in 1826 blocked the eastern drainage of meltwater, creating Laguna del Diamante on the caldera floor east of the peak, not near the summit. Historical records list four apparent Strombolian eruptions between 1822 and 1941. The first ascent was on 19 January 1883 by Paul Güssfeldt with Chilean muleteers Lorenzo Zamorano and Francisco.

The name recalls the Maipo River, fed by glaciers on the slopes and supplying valleys below for centuries. Herders sometimes still bring animals to lower grazing areas at the foot of the mountain, where old cattle trails remain visible.

Climbers need experience with high-altitude conditions and should plan several days for acclimatization before starting the ascent. Wind and sudden temperature drops make warm clothing and weather-resistant gear necessary, even in summer.

The Diamante Caldera eruption was rated 7 on the Volcanic Explosivity Index, ejecting 450 km³ of tephra, about 50% of all material erupted between latitudes 33° and 35° S during the Quaternary. Its flow travelled over 130 km. The first ascent, on 19 January 1883, was made by Paul Güssfeldt with Chilean muleteers Lorenzo Zamorano and Francisco.