Aldabra was designated a World Heritage Site by UNESCO in 1982 as a prime example of a raised coral atoll and is significantly less disturbed than most other atolls in the Indian Ocean and elsewhere in the world.

The site is classed under category Ia (Strict Nature Reserve) of the IUCN Management Category and designated as a Natural World Heritage Site for fulfilling the criteria ii, iii and iv.

The status of Strict Nature Reserve of Aldabra has been associated with the fact that the atoll fits the following criteria:

• It is an outstanding example representing significant on-going ecological and biological processes
• Aldabra contains superlative natural phenomena or areas of exceptional natural beauty
• Aldabra contains the most significant natural habitats for in-situ conservation of biological diversity

Aldabra’s unique ecosystems and species make it ecologically and scientifically valuable. Aldabra is the largest raised coral atoll on Earth and is significantly less disturbed than most other atolls in the Indian Ocean and elsewhere in the world. Aldabra is a refuge for many endangered species. These include the giant tortoise (Aldabrachelys gigantea); one of the largest congregations of nesting green turtles (Chelonia mydas) in the Indian Ocean; the world’s second largest breeding population of greater and lesser frigate birds (Fregata minor and Fregata ariel); the last flightless bird species in the Indian Ocean - the white-throated  rail (Dryolimnas cuvieri aldabranus); and a number of endemic taxa of plants and animals.