Aldabra Atoll

　　Aldabra Atoll is the world’s second-largest coral atoll, covering a total area of 60 square miles and consisting of four large coral islands, each enclosing a shallow lagoon. The coral island group is also surrounded by a coral reef. Due to its remote geographical location and inaccessibility to the general public, Aldabra has remained largely undisturbed by humans, becoming a sanctuary for around 2,000 giant tortoises. It is home to the world’s largest population of giant tortoises, hosting approximately 150,000 Aldabra giant tortoises (Dipsochelys dussumieri) on this ring-shaped coral island.

　　The entire Aldabra Atoll is encircled by coral, with its outer edge divided by three channels: two deep channels split the atoll into four major islands, containing a large, shallow lagoon fringed by mangroves, covering an area of 150 square kilometers. There are also several small islands within the lagoon. The largest of the four islands is South Island, which, together with West Island, Middle Island, and Île Polymnie, makes up the 186 square kilometers of land.

　　This isolated coral atoll in the Indian Ocean, forgotten by modern civilization, is now a particularly rich nature reserve. It is home to the world’s largest land crab—the coconut crab (Birgus latro). Due to Aldabra’s isolation, many seabirds favor it as a breeding ground. It is also the primary breeding site for both great and lesser frigatebirds in the western Indian Ocean, and supports a large population of red-tailed and white-tailed tropical birds.