Aragón's limestone canyons hide a network of abseils, jumps and swims that make the Sierra de Guara Europe's canyoning capital.
The Sierra de Guara, a few hours from Zaragoza, is riddled with slot canyons carved by mountain rivers into the limestone — the Barranco de la Peonera and Formiga among the best known — where a full day means abseiling down waterfalls, jumping into plunge pools and swimming narrow gorges with the rock walls closing in overhead.
Routes are graded from easy family canyons to committing technical descents with rappels over 20 metres, and a local guide reads the water level before choosing which one you're ready for — the same canyon can be playful in August and dangerous after spring rain.
Wear the wetsuit and helmet the outfitter gives you even on a hot day, since the water stays cold in the shade all summer, and budget a full day — you can't hike back out partway through a canyon, so once you commit to the first abseil you're in until the last one.
