Haleakalā (house of the sun) or the East Maui Volcano, is a massive shield volcano that forms more than 75% of the Hawaiian Island of Maui. The western 25% of the island is formed by another volcano, Mauna Kahalawai, also referred to as the West Maui Mountains.
The tallest peak of Haleakalā, at 10,023 feet (3,055 m), is Puʻu ʻUlaʻula (Red Hill).
From the summit one looks down into a massive depression some 11.25 km (7 mi) across, 3.2 km (2 mi) wide, and nearly 800 m (2,600 ft) deep.
The surrounding walls are steep and the interior mostly barren-looking with a scattering of volcanic cones.