Map - Rongelap Atoll (Rongelap Atoll)

Rongelap Atoll (Marshallese: Ron̄ļap, ) is a coral atoll of 61 islands (or motus) in the Pacific Ocean, and forms a legislative district of the Ralik Chain of the Marshall Islands. Its total land area is 8 sqmi. It encloses a lagoon with an area of 1,000 sqmi. It is historically notable for its close proximity to US hydrogen bomb tests in 1954, and was particularly devastated by fallout from the Castle Bravo test. The population was forcibly removed from Rongelap following the test due to high radiation levels, and later studied due to their exposure to radiation. However, according to the most recent census in 2011 it has begun to recover with about eighty people living on the atoll.

The Marshall Islands, of which Rongelap Atoll is a part, were first settled by Micronesians.

The first sighting recorded by Europeans was by Spanish navigator Álvaro de Saavedra on 1 January 1528. Together with Utirik, Ailinginae and Toke atolls, they were charted as Islas de los Reyes (Islands of the Three Wise Kings in Spanish) due to the proximity of Epiphany. Fourteen years later it was visited by the Spanish expedition of Ruy López de Villalobos.

Rongelap Atoll was claimed by the Empire of Germany along with the rest of the Marshall Islands in 1884, and the Germans established a trading outpost. After World War I, the island came under the South Seas Mandate of the Empire of Japan. The base became part of the vast US Naval Base Marshall Islands. Following the end of World War II, Rongelap came under the control of the United States as part of the Trust Territory of the Pacific Islands.