Part of the Outer Islands of the Seychelles, Aldabra is reputedly the world’s second-largest atoll and has been described as “one of nature’s treasures” and a “sanctuary”. The inner lagoon teems with marine life like eagle rays and sea turtles. It is possible to snorkel and drift along with the tide passing in or out of the lagoon as massive numbers of fish come and go through the same channels. Narrow channels between fossilized coral islands are fringed in mangrove forests supporting large colonies of nesting boobies and Great Frigatebirds. Its distinctive island fauna includes the Aldabra giant tortoise (Aldabrachelys gigantea). Approximately two-thirds of the world’s population of giant tortoises lives on Aldabra – some 100,000 out of a reported 150,000. Because of its extreme isolation in the blue of the Indian Ocean, and due to a lack of freshwater, the island has not been developed for tourism. No airport has been built, and only a handful of smaller ships with special permits are allowed to call at this unique atoll.