National preserve, southeastern shore of Hawaii island, U.S. Established in 1916, it occupies an area of 358 sq mi (927 sq km) and includes the active volcanoes Mauna Loa and Kilauea , 25 mi (40 km) apart.
Other highlights are Kau Desert, an area of lava formations near Kilauea, and a tree-fern forest that receives nearly 100 in. (2,500 mm) of annual rainfall.