With a trailhead at 10,000 feet, hikers may feel gleefully airborne when descending on the Sliding Sands Trail into the vast eroded valley pocked with volcanic cones on Haleakala volcano. A network of colorful paths interconnect several rustic cabins and geologic wonders, like "the bottomless pit." Many hikes wind up with double-digit round-trip miles and nearly a half-mile in elevation loss. The Halemau'u Trail begins at a slightly lower elevation on the other side of the valley, but also makes a big drop.
A word of advice: On the way down remember that you have to come back out. High altitude and temps that can range from scorching to freezing in one afternoon can make the chore more difficult. You can get well into Haleakala on a shorter day hike without turning it into an ordeal. Check with rangers about renting a cabin and staying overnight on the longer hikes; if you haven't planned ahead, you may get lucky and nab a cancelation. Maui Trailblazer, pages 156 to 160, details a number of hikes in Haleakala National Park.