Tronador is the giant of the region — a 3,491 metre extinct volcano on the Chilean border, with three peaks and eight glaciers tumbling off its slopes. It is far enough from Bariloche (90 km on a winding gravel road) that the full-day trip is a serious excursion, but the views along the way and at the end are exceptional.
Most visitors stop at Pampa Linda, a clearing with a refugio and the trailheads for longer treks, before continuing to the Ventisquero Negro viewpoint and the base of the Garganta del Diablo waterfall. Tour operators in Bariloche run daily summer buses; the road is one-way uphill in the morning and downhill in the afternoon to manage the traffic.