What is the largest raised coral atoll in the world?

Aldabra is widely described as the world’s largest raised coral atoll, although Kiritimati is larger by total atoll area and Aldabra is often described more precisely as the largest raised coral reef.

Aldabra Atoll lies in the western Indian Ocean and belongs to the Seychelles. Its four main islands form a ring around a large, shallow lagoon. Much of the land consists of ancient coral limestone that was raised above sea level by geological uplift and has been shaped by changing sea levels over tens of thousands of years.

The wording matters because “largest coral atoll” alone can point to Kiritimati, in Kiribati, which is generally regarded as the world’s largest atoll by land area. Aldabra’s distinction is its raised structure: it is an elevated coral atoll rather than a low-lying ring barely above sea level.

Aldabra is also famous for its isolation and wildlife. It supports the world’s largest population of Aldabra giant tortoises and became a UNESCO World Heritage Site in 1982.