The Bahamas is a coral-based archipelago in the Atlantic Ocean. Its 700-plus islands and cays range from uninhabited to packed with resorts. The northernmost, Grand Bahama, and Paradise Island, home to many large-scale hotels, are among the best known. Scuba diving and snorkeling sites include the massive Andros Barrier Reef, Thunderball Grotto (used in James Bond films) and the black-coral gardens off Bimini.