Atoll of an atoll is very small in comparison to the total area. Atoll islands are low lying, with their elevations less than 5 meters (9). Measured by total area, Lifou (1146 km²) is the largest raised coral atoll of the world, followed by Rennell Island (660 km²). More sources however list as the largest atoll in the world in terms of land area Kiritimati, which is also a raised coral atoll (321.37 km² land area; according to other sources even 575 km²), 160 km² main lagoon, 168 km² other lagoons (according to other sources 319 km² total lagoon size). The
Johnston Atoll Johnston Atoll Johnston Atoll, also known as Kalama Atoll to Native Hawaiians, is an unincorporated territory of the United States currently administered by the United States Fish and Wildlife Service. Johnston Atoll is a National Wildlife Refuge and is closed to public entry. Limited access for management needs is only by Letter of Authorization from the U.S. Air Force and Special Use Permit from the U.S. Fish and Wildlife Service. For nearly 70 years, the atoll was under the control of the U.S. military. During that time, it was variously used as a naval refueling depot, an airbase, a nuclear