Rongelap Atoll ( Marshallese : , ) 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 . 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 . The population was evacuated from Rongelap following the test due to high radiation levels , however according to the most recent census in 2011 it has begun to recover with about eighty people living on the atoll . 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
Castle Bravo
Castle Bravo
Rongelap Atoll