The larger islets are : Its first recorded sighting was by the Spanish navigator Álvaro de Saavedra on board of the ship '' Florida '' on 29 December 1527 . Together with Rongelap , 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 . Utirik Atoll was claimed by the Empire of Germany along with the rest of the Marshall Islands in 1884 . After World War I , the island came under the South Pacific Mandate of the Empire of Japan . Following the end of World War II , Utirik came under the control of the United States as part of the Trust Territory of the Pacific Islands . Utirik was one of four atolls affected by nuclear fallout from Castle Bravo , the largest of the many nuclear weapon tests conducted at Bikini Atoll immediately following World War II . Research is still being done to ascertain the radiation levels , though many scientists agree that there is no harmful effect from the radiation still present . The island has been part of the independent Republic of the Marshall Islands since 1986
Castle Bravo
Castle Bravo
Utirik Atoll