Some might call plunging dozens of feet down a thundering torrent of icy glacier melt into a foaming natural pool a leap of faith. Yet every summer, thrill-seeking canyoneers from all over Europe flock to Austria's Tyrolean Alps to explore its rugged, 10,000-foot-high mountains, densely wooded valleys, shimmering glaciers, and quaint alpine villages. There, equipped with ropes, climbing harnesses, helmets – and generous doses of chutzpa – these thrill-seekers jump, swim, slide, and rappel down every manner of steep mountain gorge. A word to the wise: If you find yourself dangling from a slippery, narrow rock shelf 30 feet above an icy pool of glacier melt, remember to wrap your arms tightly around yourself before hitting the water so you don't dislocate a shoulder. Such are the everyday concerns here.

One of the best places to try out canyoneering is the Ötztal, a spectacular 40-mile long valley southwest of Innsbruck (which also lent its name to "Otzi the Iceman" – the 5,400-year-old Stone Age hunter whose preserved body was discovered in 1991 in the ice of a nearby glacier.) You can also hike spectacular high alpine routes like the so-called Knappensteig Miner's Trail. In this unspoiled terrain, the only other travelers you're likely to encounter are chamois, marmots, and mountain jays – and perhaps the occasional mountain goat, peering curiously down at you from atop the steep rocky ledges.

At the end of a day of hiking or canyoneering, it's local custom to take in a soak in the otherworldly Aqua Dome: a space-age, 6,500-square-foot spa complex on the outskirts of the village of Längenfeld. The Aqua Dome's three flying saucer-like outdoor thermal pools face the base of Längenfeld's imposing glacier. Behind them, the enormous enclosed central dome contains more massive indoor whirlpools and massage pools filled with revitalizing mineral waters that bubble up from nearly 4,000 feet below.

Once inside, the Gletscherglühen sauna and steam bath complex offers herb or brine vaporizing steam baths, as well as a sauna made of wood, stone, and glass (the more traditional Finnish sauna has tiers of wooden benches). As is the custom with public saunas in much of Europe, Gletscherglühen is clothing optional, which means that its rejuvenating combination of blazing heat, freezing temperatures, fragrant steam, and icy rain is not for the bashful. Otzi the Iceman would fit right in.

More information:To learn more about the Ouml;tzal Valley's wide range of year-round outdoor adventure, visit oetztal.com. The Aqua Dome, the only hot springs spa in West Austria, is a public spa on the outskirts of Längenfeld. It offers a glass-domed swimming pool, whirlpools, steam rooms, and an outdoor plunge pool, as well as an attached four-star wellness hotel.