Located just off the tip of Mexico’s Yucatan Peninsula, Ambergris is Belize’s largest island (or caye) at 25 miles long and just over a mile wide. The barrier reef is only a quarter of a mile from the beach, making diving and snorkelling easy and accessible. The only town is San Pedro, home to the majority of the island’s population, as well as some bars, restaurants and hotels – there are many more resorts stretching to the south and north to the Mexican border. Just offshore lie the popular diving/snorkelling sites of Shark and Ray Alley and Hol Chan Marine Reserve – over 160 species of fish have been identified in the reserve, along with nearly 40 species of coral. Further offshore there are the many dive sites found around the Turneffe Islands and at Lighthouse Reef, including the famous Blue Hole, a former dry land cenote (sunken cave) once visited by Cousteau, where you can see stalactites 30m down.