Hawaii, island (1990 pop. 120,217), 4,037 sq mi (10,456 sq km), largest and southernmost island of the state of Hawaii and coextensive with Hawaii co.; known as the Big Island. Geologically the youngest of the Hawaiian group, Hawaii is made up of three volcanic mountain masses rising from the floor of the Pacific Ocean—Mauna Kea (13,796 ft/4,205 m above sea level, the highest point in the state); Mauna Loa (with the huge Kilauea crater); and Hualalai. Lava flows, some of which reach the sea, and volcanic ash cover parts of the island. The north and northeast coasts are rugged with high cliffs; the west and south coasts are generally low, with some good bathing beaches. An unusual black-sand beach lies on the southeast coast. Short rivers radiate from the major summits; Wailuku River, the longest, flows into Hilo Bay. Many waterfalls are on the island. Hawaii has a tropical-rainy climate, with the north and east slopes receiving the most rain. The west and south slopes are much drier; the Kau Desert is in S Hawaii. Temperatures decrease with elevation; Mauna Loa and Mauna Kea are usually snow-covered in winter. Vegetation varies from tropical rain forest to grasslands to barren volcanic areas. Sugarcane and pineapples are the island's principal products. The Kona district of W Hawaii is the coffee belt of the United States and is also known for its health resorts and offshore deep-sea fishing. Hilo, on the east coast, is the island's largest city and chief port and is the county seat. A highway, linking the coastal towns, encircles the island. At Kealakekua Bay there is a monument to Capt. James Cook, the first English explorer to visit (1778) the Hawaiian islands. Hawaii Volcanoes National Park and Pu'uhonua o Honaunau National Historical Park are on Hawaii (see National Parks and Monuments, table). All over the island heiaus (ancient temples) are found.