Nevado Tres Cruces, Volcanic mountain in Atacama Region, Chile and Tinogasta Department, Argentina.

Nevado Tres Cruces is a volcanic massif on the Chile-Argentina border, a north-south chain about 10 km long and 5 km wide made of at least three overlapping volcanoes. Its three main summits are Tres Cruces Sur (6,748 m), Tres Cruces Centro (6,629 m) and Tres Cruces Norte (6,206 m); the southern, least eroded summit has two explosion craters and a summit lava dome.

Nevado Tres Cruces was first climbed in 1937 by the second Polish expedition, which reached the summit of the massif. The volcano itself has been active for at least 1.5 million years, with major ignimbritic eruptions 1.5 million and 67,000 years ago and a last eruption about 28,000 years ago.

The massif closes the volcanic chain that borders the San Francisco pass to the south, running from San Francisco and Incahuasi through El Fraile, El Muerto and Ojos del Salado to Cerro Solo and Tres Cruces. Its name, Three Crosses, refers to the three summits ordered south to north: Sur, Central and Norte.

Access to the mountain requires traveling through Copiapo and Paipote via the Camino Internacional route toward Portezuelo Santa Rosa. The journey is demanding and requires preparation for high altitude and extreme weather conditions.

Nevado Tres Cruces Sur, at 6,748 m, is the sixth-highest mountain in the Andes and the least eroded of the massif's volcanoes. It consists of two overlapping cones: the older western one holds two explosion craters, while the eastern one is capped by a summit lava dome. Small glaciers cling to its eastern and southern flanks above 5,500 m.