There are only four atolls in the Caribbean and three of them can be found off coast of Belize. These are Lighthouse Reef, Glovers Reef and Turneffe Islands.
The famous Blue Hole is a symmetrical ocean-filled sinkhole that is 400 ft deep and 1000 ft wide. Tens of thousands of years ago it was a limestone cave and when sea levels rose the ceiling of the cave collapsed revealing the Blue Hole as it is today. Divers descend to see the stalactites and stalagmites that were once inside the cave. It is located in the centre of the Lighthouse Reef Atoll. Its magnitude and shape is probably best appreciated from the air and helicopters can be chartered for this purpose.
This was the first marine conservation area in Belize. It has a lighthouse, several wrecks and is a sanctuary to a population of several thousand of the rare red-footed boobies.
This is the largest and most accessible of the three atolls and offers plenty of excellent dive sites. There are also resorts on the islands with diving services.
South of the other atolls and the least accessible it offers excellent diving opportunities and spectacular coral formations.
This protected area not only contains the beautiful Silk Cayes but is also visited by Whale Sharks during the months of March to June around the full moon. The Whale Sharks come in huge numbers to feed off the spawning Cubera snappers. The reserve is located about 40 minutes from Placencia and fast boats take both snorkellers and divers to see the Whale Sharks. Guides must be trained to minimize the impact on the Whale Sharks and the number of boats within the reserve are restricted during the Whale Shark season.