Haleakalā National Park10,023-foot dormant volcano, sunrise above the clouds, and the bamboo forest at the bottom of the Pīpīwai Trail

Haleakalā — Hawaiian for "house of the sun" — is a dormant shield volcano whose 10,023-foot summit caps the eastern half of Maui. The crater you see from the summit is not technically a volcanic crater but an erosional valley seven miles long, two miles wide, and 2,600 feet deep — the result of two windward valleys eroding into each other over half a million years. The volcano last erupted around 1600 CE and is still classified as active.

The Summit District is best known for sunrise — when the air is coldest, the trade winds quietest, and the sun lifts above a 5,000-foot deck of clouds with the West Maui Mountains poking through to the west. Reservations are required between 3 and 7 AM (book exactly 60 days ahead at 7 AM HST), the access road climbs from sea level to 10,023 feet in 38 miles, and the temperature at the top runs 30°F colder than Wailea. The Sliding Sands trailhead descends 2,500 feet into the crater past cinder cones the rangers call the "Pele's Pots."

The Kīpahulu District sits 60 miles east at sea level — the back end of the Road to Hana — and feels like a different planet. The four-mile Pīpīwai Trail climbs through a banyan grove and a half-mile stretch of bamboo so dense the trail is dim at noon, ending at 400-foot Waimoku Falls. The Pools of ʻOheʻo (sometimes called the Seven Sacred Pools) stair-step down to the ocean directly below the Kīpahulu Visitor Center; swimming is allowed when the rangers post the area open. Plan a full day for either district; the two are not connected by road inside the park.