The French Frigate Shoals (Hawaiian: Kānemilohaʻi) is the largest atoll in the Northwestern Hawaiian Islands. Its name commemorates French explorer Jean-François de La Pérouse, who nearly lost two frigates when attempting to navigate the shoals. It consists of a 20-mile (32 km) long crescent-shaped reef, twelve sandbars, and the 120-foot (37 m) high La Perouse Pinnacle, the only remnant of its volcanic origins. The total land area of the islets is 61.508 acres (24.891 ha). Total coral reef area of the shoals is over 232,000 acres (94,000 ha). Tern Island, with an area of 26.014 acres (10.527 ha), has a landing strip and permanent habitations for a small number of people. It is maintained as a field station in the Hawaiian Islands National Wildlife Refuge by the United States Fish and Wildlife Service.