Aldabra Atoll + Islands

Aldabra is a raised coral atoll on the western side of the archipelago, closer to Africa, and has been basically untouched by humans including the Persians and Arabs who found the island before the Portuguese arrived in 1511. For this reason, it is truly a natural wonder because it has been virtually unchanged for thousands of years.

UNESCO World Heritage Site

The atoll is made up of four large islands made of coral that surrounds a shallow lagoon. There is a coral reef that encircles these four islands. The island is not easy to access and for this reason it still has the largest population of giant tortoises in the world.

The main importance of this untouched ecosystem is for the study of evolutionary and ecological processes. The extraordinary beauty of this atoll is derived from the diversity of the ocean and land, which join to make a spectacular array of formations and colours.

The Geography

The four main islands are built form coral limestone. They are separated by narrow passages and encircle a shallow lagoon. Inside this lagoon is a spectacle of natural phenomena and includes many smaller islands. The entire outside of the atoll is surrounded by a fringing reef.

The development of the different landforms has created several different marine habitats including coral reefs, sea-grass beds and mangrove mudflats. The oceanic island ecosystem developed without human interruption. The land surface is mostly ancient coral reef that is about 125,000 years old that has been continually raised above sea level. There is great diversity of landforms that support an assortment of island communities with the top of the food chain being the giant tortoise, which is an herbivore. This is unusual. The tortoises feed on the shrubbery and grasses, which have evolved a growing pattern in response to the tortoises grazing pattern.

Aldabra Atoll is a fascinating laboratory with over 400 endemic species and subspecies that include vertebrates, invertebrates and plants. It supports over 100,000 giant tortoises. This is the last place they reside in the Indian Ocean where they once were on many islands. A few hundred were transplanted to Curieuse another island in the Seychelles.

The atoll is also an important breeding ground for endangered green turtles and critically endangered hawksbill turtles. Several species of birds are endemic to the island such as the last flightless bird of the Western Indian Ocean. There are several large water bird colonies including one of only two existing oceanic flamingo populations and the second largest colony of frigate bird in the world. The ecosystems are intact and sustain the viable populations of all the key species.

Giant Tortoises are not the only animals sustained by the island. The coconut crab, the largest land crab in the world lives there as well as hammerhead sharks, barracuda and manta rays. In ancient times, the dominant land predator was the crocodilian Aldabrachampsus, a horned crocodile of which some remains from the Pleistocene were found on the island.

The island is managed by the Seychelles Islands Foundation. They limit tourism and oversee protection of the ecosystems from invasive alien species, oil spills and climate change.

A Close Call

Aldabra was not always considered ecologically important. In the 1960s, the British government considered putting a Royal Air Force base on the island and asked the United States to help. The US would get a base too if they helped fund the project. Also, the BBC wanted to put transmitters on the island to rebroadcast the BBC Overseas Service to Africa. Fortunately, international ecologists protested, and the military plans were abandoned. The BBC couldn’t do it alone. At this time, the atoll received full protection and was designated a UNESCO World Heritage site in 1982.

The only permanent population on the island is the Island Manager, the Research Officer and rangers and staff.

How to see Aldabra?

People wishing to visit Aldabra must get permission from the Seychelles Islands Foundation at their head office. Tourism increases the revenue needed to support the conservation and protection of Aldabra, but tourism is strictly limited to nature tourism and education.

Permission for tourism is only given to:

• Small and medium sized cruise ships
• Live-aboard charter boats
• Private yachts
• Live-aboard dive boats
• Educational and Scientific visits on land that are limited to 12 persons at a time

Visitors are given limited access according to the zoning policy and the visits are lead in a sustainable way with any impact on the atoll constantly being assessed.

Visitors may not collect shells or in any way interfere or damage the plants and animals. No geological or biological specimens can be collected and there are strict sanitary methods that apply to all visitors. A staff member must always be with visitors and they may not wander around the island unaccompanied.

Transportation to Aldabra

There is a bi-monthly supply boat that belongs to the Island Development Company that will take visitors to the island. However, this needs to be arranged by the visitors once permission is granted. The SIF may help, but it is not their responsibility to arrange transportation to Aldabra. Chartered planes can be taken to Assumption where a chartered boat can be taken to Aldabra.

Visitors can also hire a private yacht once they have received permission to visit the island. It is possible to drift dive into the lagoon depending on the tide and the marine life there is exceptional. Only about 1000 people visit Aldabra every year, so the birds and other animals are not afraid of humans. This means it is possible to have very close observation.


There is a daily landing fee for all foreign visitors as well as a fee for professional photographers and journalists. There is a fee for still photographs as well as for video photography. The fees are all applied to the continuing conservation of the island.

Aldabra is a natural wonder almost completely untouched by humans for thousands of years. For the few visitors who get to the island, the experience is extraordinary.