The Marshall Islands are a sprawling chain of volcanic islands and coral atolls in the central Pacific Ocean, between Hawaii and the Philippines. In the northwest, Bikini Atoll’s largely undisturbed waters, used as a ship graveyard after World War II, are now a popular wreck dive site. Near Majuro Atoll, which holds the islands' capital and largest settlement, the coral reef at Kalalin Pass teems with marine life.