Walking on Water & Other Adventures for Serious Trekkers -- One of the crazier (or more adventurous) treks is the arduous 16-day Chadar Trek along the Zanskar River, sufficiently semifrozen to support your weight for 2 months of the year. For 4 days (one-way) you trek on slippery ice and occasionally climb around open water on this ancient trade route; at night, outside temperatures plummet to a bone-chilling 3.8°F (-15°C). By day (when it's a mere 23.8°F/-4°C or so) the challenges are many, but the setting is awesome and there's always the chance of meeting local Zanskaris. One of the best operators offering this trek is Project Himalaya (tel. 977/98-0214-9789 in Kathmandu; www.project-himalaya.com; info@project-himalaya.com), a Kathmandu-based company with good ethics and a somewhat unformulaic approach to its routes. Also taking in parts of Zanskar is the Markha Valley Trek (10-12 days) -- considered one of the most exhilarating and varied on earth -- undertaken by Himalayan River Runners (www.hrrindia.com) You cross two Himalayan passes at altitudes over 4,500m (14,760 ft.) and descend into the Zanskar Valley before finishing the in upper parts of the Markha, surrounded by jagged peaks. Banjara offers an 8-day version that follows the riverbed more closely and includes one very high pass. Bajara also offers a 2-week trek that culminates at Lamayuru, one of the most enchanting monasteries in Ladakh, and reached by way of some truly intense scenery. If you're wanting to climb the Stok Glacier (traversing altitudes over 4,800m/16,000 ft.), contact Rinchen Namgial at Yama Adventures (www.yamatreks.com), who will make all the necessary arrangements (and get the special license required). Also ask about treks to Pangong Tso and Tso Moriri.

Rafting in Ladakh -- Without doubt, Zanskar offers one of the most exhilarating and challenging white-water rafting journeys in India. Beginning on the Stod River in Zanskar -- "the land of white copper" -- the multiday river adventure descends through rapids of Class IV and V, passes incredibly desolate, scenic gorges and stupendous cliffs down the Zanskar River, and ends on the Indus, near Alchi Monastery. The adventure takes a minimum of 12 days round-trip from Leh and is best attempted as part of an organized expedition. Aquaterra Adventures (tel. 011/2921-2641 or -2760; www.treknraft.com) is possibly the best choice for discerning travelers looking to raft the Indus or Zanskar rivers, and the very professional Mercury Himalayan Explorations (www.himalayanadventure.com) does a number of all-inclusive trips that combine several days of rafting with sightseeing and general exploration. If you're looking for something less hairy, there are tamer options close to Leh: a half-day rafting trip from Nimoo to Alchi that's got some adrenaline packed in, a 3-hour gentle rafting trip from Hemis to Choglamsar where your guide does most of the paddling work with well-practiced efficiency, or a 4-hour trip from Phey to Nimoo that packs in a bit of both. Enquire about daily trips through Rimo Expeditions (www.rimoexpeditions.com) which also does 12-night trips down the Zanskar Gorge. For a slightly more gentle river-riding experience, upmarket Shakti (tel. 0124/456-3899; www.shaktihimalaya.com) offers a 3-day rafting trip in the Nubra Valley, with nights spent in above-ordinary camp sites.

Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.