El Solo volcano is large stratovolcano in Argentina at the border with northern Chile and west of Nevados del Ojos de Salado and SE of Tres Cruces volcano.
Is comprises 9 eruptive centers. The age of its last eruptions is unknown, but was during the Holocene (less than 11,700 years ago), when it produced thick rhyodacitic pyroclastic-flow deposits that fill adjacent valleys.