Lastarria, Stratovolcano in Antofagasta Region, Chile.

Lastarria is a stratovolcano in the northern Chilean Andes, near the Argentine border, in the Antofagasta Region. Its cone is built from layers of solidified lava and ash deposits that have accumulated over many eruption cycles.

Lastarria began forming during the Pleistocene and took its current shape through repeated eruptions over a long period. Each eruptive phase added new rock layers, gradually building the cone that can be seen today.

In Andean tradition, high mountain peaks like this one are seen as living beings called Apus, believed to watch over the surrounding land and its people. Offerings are sometimes left near the base of such mountains during local ceremonies.

Reaching Lastarria requires solid experience at high altitude and appropriate gear for cold and wind, since the area has no infrastructure nearby. Planning the visit with a professional guide is strongly recommended, as the terrain is demanding and conditions can change fast.

Lastarria is the largest source of volcanic gases in its region, and its fumaroles have left vent deposits and flows of molten sulfur on the northern side and inside the craters. The name Azufre, sulfur, comes from these deposits; the salt pan Laguna de la Azufrera just north is named after them too.