Where can you hover above coral gardens, drift along the Caribbean's longest barrier reef, explore three immense coral atolls and descend into the world's largest blue hole? The answer is Belize. While Belize is a unique underwater destination, visitors to this tiny Central American nation will find two countries in one.Coastal and offshore Belize is distinctly Caribbean, while the interior of the country is more typically Latin American. Offshore is a world of blue water, golden coral reefs and hundreds of islands and islets, some smothered in a froth of mangroves, others mere slivers of bleached white sand. The interior is a varied wilderness of mountains, rivers and marshes, savannas, low jungles and highland rain and pine forests. Bone-white pyramids rise above the forest, vestiges of the great Mayan cities that flourished here until about 900 A.D. Though only about the size of Massachusetts, Belize features a smorgasbord of eco-adventures, including the big three: reefs, ruins and rain forests. Belize's underwater credentials are impeccable: There are 170 miles of nearly continuous barrier reef, the second-greatest stretch of reef in the world, eclipsed only by Australia's Great Barrier Reef. Farther offshore are three of only four true coral atolls found in the Caribbean. Fringing reefs wrap around hundreds of islands interspersed between the shore and the outer atolls. While thousands of divers now visit Belize each year, considering the reef area available, that number of visitors is just a drop in the ocean. Belize City is an excellent choice for those who are looking for access to the two worlds of Belize. Two large, modern hotels and several quaint guesthouses offer daily dive trips to the barrier reef and atolls. Also docked in Belize City are several live-aboard dive vessels that serve as one of the best ways to experience underwater Belize. Ambergris Caye, the country's largest island, is the most popular offshore destination. Resort hotels, dive operators, restaurants, shops and bars are conveniently located along the beach in and near San Pedro town. A section of the barrier reef, a shark dive site and a marine park are found just offshore. Dive boats make trips to the atolls on most days. Other vacation-oriented islands, such as Caye Caulker and St. George's Caye, are close by. Several dive resorts are located on Turneffe Island's atoll -- the largest and closest atoll to shore. Nearly 70 dive sites circle Turneffe, which is famous for its prolific marine life. Lighthouse Reef Atoll and Glovers Atoll have one dive resort each. Lighthouse features many renowned wall-dive sites, the bird sanctuary at Half Moon Caye and the famous Great Blue Hole of Belize. The Great Blue Hole, a geological relic from the last Ice Age, is a nearly perfect circle -- 1,000 feet in diameter and 440 feet deep. Below is a cavern decorated with huge stalactites, some 35-feet long. Glover's Reef, the southernmost atoll, offers pleasant isolation and one of the least-dived undersea environments in Belize. Many miles of pristine pinnacle and wall diving surround the atoll, and there are hundreds of patch reefs inside its lagoon. The frontier of diving in Belize is the southern peninsula of Placencia, reached from Belize City by air or road. Uncrowded and sparsely developed, the peninsula's casual accommodations and two villages are arranged along the best stretch of beach in Belize. Offshore are delicate coral gardens, precipitous walls and, if you are lucky, migrating pilot whales and whale sharks. Belize is the heartland of the ancient Mayan civilization and it boasts more than 15 major sites now operating as archaeological parks. The largest is the city of Caracol in western Belize. Its main pyramid, Caa-na, is the country's tallest man-made structure. At one time, more than 200,000 Mayans populated Caracol, more people than live in all of Belize today. For more information about visiting Belize, click on the home page below.