Marshall Islands Atolls ArnoArno Arno wasn't used as a nuclear testing site like several neighboring atolls, but its environment has been preserved.Bikini AtollBikini Atoll Bikini Atoll is unfortunately famous for the nuclear testing that occurred there over half a century ago. Some of its islands have reopened for diving and other activities.EnewetakEnewetak Unlike many atolls, Enewetak was formed from an underwater mountain called a seamount. Enewetak was another nuclear testing site, and cleanup continues today.KwajaleinKwajalein When explorers first landed here they called it "The Gardens" for its lush trees and tropical flora. The atolls is now slowly starting to recover after nuclear testing.MajuroMajuro Majuro is one of the largest coral islands in the Pacific and the hub of the Marshall Islands. The atolls is well known for tourism, environment and coconut oil exports.RongelapRongelap Rongelap consists of 61 islands. It was close to a hydrogen bomb test in the 1950s, and now lacks much of the biodiversity of other atolls.