Castaño Overa Glacier, Mountain glacier in Nahuel Huapi National Park, Argentina.

Castaño Overa Glacier descends from Mount Tronador's slopes at roughly 1,900 meters elevation, displaying deep blue crevasses and layered ice formations shaped by time. The surface shows rough textures and steep drops created by the slow movement and melting of ice over many years.

The glacier formed during ancient ice ages and has shaped Mount Tronador's landscape for thousands of years. Since the 1900s it has shrunk significantly, with its size today much smaller than in previous centuries.

The Otto Meiling refuge, set between the Castaño Overa and Los Alerces glaciers, is the usual starting point for expeditions to the summit of Mount Tronador. Trekkers reach the glacier on foot, and the ridges separating it from neighbouring glaciers on the Argentine side draw walkers as well.

The hike to reach it takes about four hours from Pampa Linda, passing through forests and rocky terrain where good boots are essential. The Otto Meiling refuge along the route provides shelter and serves as a good place to rest before or after the main walk.

The Otto Meiling refuge, sitting between the Castaño Overa and Los Alerces glaciers, is the usual starting point for expeditions to the summit of Mount Tronador. The ridges separating Castaño Overa from the other glaciers on the Argentine side are themselves a draw for climbers and hikers.