Bikini (bēkēˈnē) [key], atoll, c.2 sq mi (5.2 sq km), W central Pacific, one of the Ralik Chain, Marshall Islands. It comprises 36 islets on a reef 25 mi (40 km) long. After its inhabitants were removed (1946) to Rongerik, Bikini was the scene of 23 U.S. atomic and hydrogen bomb tests (1946–58). The natives were transferred from Rongerik to Ujelang in 1947 and in 1949 were resettled on Kili. Bikini was declared safe for habitation in 1969. In 1974, 100 natives returned, but they were evacuated in 1978 when new data showed high levels of residual radioactivity. A cleanup began in 1988. By the late 1990s, Bikini had become a popular destination for scuba divers, though it remained uninhabited pending completion of the cleanup. Bikini was formerly called Escholtz Island.