Volcán Chillán — more precisely the Nevados de Chillán volcanic complex — rises to 3,212 metres above the Termas de Chillán resort. It is one of Chile's most active volcanoes, with regular eruptions recorded since the 18th century. In summer, when the snow has melted from the lower slopes, hikers can approach the active cone on marked trails from the resort. The landscape is stark and dramatic: sulphurous fumaroles, ash-grey slopes, and the ice-capped peaks of the high Andes behind.
Trails should only be undertaken with current condition checks — the volcanic activity level changes, and trails are sometimes closed. The national park authority and the resort management maintain current information. The full ascent to the crater rim is for experienced hikers with proper equipment; the lower approaches are accessible to fit visitors with good boots. The views from altitude over the Ñuble valley and toward the Pacific coast on clear days are exceptional.