Biking -- The Atacama region offers excellent terrain for mountain-bike riding, including the Quebrada del Diablo (Devil's Gorge) and Valle de la Muerte (Death Valley); however, it is also enjoyable to ride across the flat desert to visit sites such as Tulor. Bike rental shops can be found along Caracoles, and they all are the same in terms of quality and charge about $8 (£5.30) per day.
Horseback Riding -- Horseback riding is a quiet, relaxing way to experience the Atacama and view Indian ruins that are inaccessible by bike. If you are adept at galloping, fulfill your Lawrence of Arabia fantasies and race across a sand dune. Rancho Cactus, Toconao 568 (tel. 55/851506; www.rancho-cactus.cl), and La Herradura, Tocopilla s/n (tel. 55/851087; email@example.com), offer short and full-day rides to a variety of destinations for an average of $8 (£5.30) per hour. They also plan overnight trips; consult each agency for details and prices. La Herradura has the slight edge with quality of horses; however, Farolo and Valérie at Cactus are more fun.
Sandboarding -- Sandboarding is the sand-dune version of snowboarding. Several places in San Pedro rent boards, and the place to head is Valle de la Muerte. It's best to go by bike or car. The more similar the bindings on your board to snowboard bindings, the easier it will be to keep your balance. Also, take the more tapered, slightly longer boards instead of those short, wheel-less skateboards some places offer. No ski lifts here -- don't forget to take water and sun block on this excursion, as you'll spend lots of time climbing back up the steep dunes in the heat.
Volcano Ascents -- Climbing one of the four volcanoes in the area requires total altitude acclimatization and good physical condition. It is a heart-pounding hike up, but if you can hack it, the sweeping views and the experience in itself are exhilarating. The most popular ascent is up the active Volcano Láscar to 5,400m (17,712 ft.), about a 4-hour climb, and leaves San Pedro before sunup. However, recent activity means this climb may not be available. Volcano Lincancabúr is also popular, but it requires an overnight stay at a rustic refugio just across the border and a Bolivian guide. Many tour companies offer these excursions; among the best is Azimut 360, Caracoles s/n (tel. 2/235-1519; www.azimut.cl).