Bikini atoll. Photograph of Bikini Atoll in the Pacific Ocean. Bikini is an atoll (island of coral that encircles a lagoon) in the Micronesian Islands and is part of the Republic of the Marshall Islands. Between 1946 and 1958 the atoll was used as a nuclear weapons testing site but the native Bikinians returned to their homes in the early 1970s. On 1st August 2010 the World Heritage Committee inscribed the Bikini Atoll Nuclear Test Site on the World Heritage List for the role that it played in shaping global culture in the second half of the 20th Century. Image taken by an astronaut using a hand-held camera on board a spacecraft, in 1993.