Benasque is the traditional base camp for excursions to Aneto, which, at 11,168 feet, is the highest peak in the Pyrenees. You can rent crampons and a piolet (ice ax) for the two- to three-hour crossing of the Aneto glacier at any sports store in town or at the Refugio de la Renclusa, a way station for mountaineers that's an hour's walk above the parking area, which is 15 km (9 miles) north of Benasque, off A139. The trek to the summit and back is not difficult, just long—some 20 km (12 miles) round-trip, with a 4,500-foot vertical ascent. Allow a full 12 hours.
Benasque, 22440, Spain