Nevado Anallajsi, Volcano summit in Oruro Department, Bolivia

Chua Chuani, also called Nevado Anallajsi, is a stratovolcano in Bolivia built mainly of andesite and dacite. It covers 368.8 square kilometres and rises above a plateau of ignimbrite. Its youngest lava flows appear to have come from a vent on the north flank; the date of the last eruption is unknown.

Nevado Anallajsi is a stratovolcano built mainly of andesite and dacite, overlying a plateau of ignimbrite. Its age is debated: erosion state suggests about 10.2 million years, while other estimates give 2.6 million years. The date of its last eruption is unknown, but its youngest lava flows appear to have come from a vent on the north flank.

The sources record the name Nevado Anallajsi, not a herb-derived name; no document mentions chuwa chuwa plants or their use. The volcano is a stratovolcano of andesite and dacite lying over an ignimbrite plateau, and its youngest lava flows appear to have come from a vent on the north flank. Its last eruption date is unknown.

Reaching the summit requires specialized equipment and time for acclimatization due to the high altitude and changing weather. Visitors should prepare for difficult conditions and variable weather patterns.

The youngest lava flows appear to have come from a vent on the north flank, so the last eruption date remains unknown. Estimates of the volcano's age differ widely, from 2.6 to 10.2 million years, based on how eroded it is.