The name Cosmoledo honours António (or Antão) Gonçalves Cosme Ledo who sailed to India in 1537 as pilot of the vessel Flor de la Mar, becoming patron chief before returning to Portugal in 1545 aboard the São Joao.

Menai and Wizard Islands were named after ships that explored the atoll on the Moresby Expedition in 1822.

Cosmoledo was settled shortly after this and a visitor in 1895 noted 200-300 coconut trees, maize and goats.

Exploitation of guano on North-east Island was taking place in 1901, when 120 tons had been removed.

On the western coast, elevated reef rock forms undercut headlands mirroring the waves of the sea and separated by sandy beaches.

It also has the Indian Ocean's largest population of red-footed booby censused by the Island Conservation Society as about 15,000 pairs.

Cosmoledo also has Seychelles' largest colony of sooty tern breeding on the northern end of Wizard Island.

The lagoon is an important feeding ground for migratory waders, with crab plover and ruddy turnstone most common.

The flora is similar to that of Aldabra, with fewer species but including several plants endemic to the group.

Green turtle nest in reasonably large numbers, despite decades of exploitation in the past and poaching in the present.