Rongelap Atoll (Marshallese: , ) or Namorik Atoll 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 only , but it encloses a lagoon with an area of . 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. Only 20 people live there now, a fraction from the originally more than 300.