Mauna Kea (White Mountain) is Hawaii's highest peak, and its 4140m (13,796ft) summit has a cluster of observatory domes, containing what is considered the greatest collection of astronomical telescopes in the world. The Onizuka Center offers displays and stargazing, while a rugged 9.7km (6mi) hiking trail leads from here to the summit.
Pu'uhonua O Honaunau National Historical ParkPu'uhonua O Honaunau National Historical Park comprises ancient temples, royal grounds, burial sites and a pu'uhonua (place of refuge). Explore the carved-wood representations of ancient gods; the stone board for konane, an ancient form of checkers played with black lava and white coral; and the wonderful snorkelling found off some natural lava steps.
Hawai'i Volcanoes National ParkUnique among American parks, Hawaii Volcanoes National Park contains two active volcanoes and terrain ranging from tropical beaches to the sub-arctic, 4103m (13,679ft) summit of Mauna Loa. The centrepiece is Kilauea Caldera, the still-steaming sunken centre of Kilauea Volcano. Rangers can provide the lowdown on guided walks and trail conditions.
Kealakekua Bay State Historical ParkKealakekua Bay is one of the Big Island's (and the state's) premier snorkelling spots. In the pristine waters, a spectacular diversity of marine life thrives. The bay is both a state park and a marine-life conservation district. Among the protected species here are spinner dolphins that frequently swim into the bay.
Mo'okini HeiauOn the northernmost tip of the island, Mo'okini Heiau is one of the oldest and most historically significant temples in Hawaii. Charts date the temple back to AD 480, when human sacrifices were offered to the war god Ku. Because so few people come this way, chances are you'll be alone with the wind and the spirits.