Bassas da India is an uninhabited, roughly circular atoll located in the southern Mozambique Channel, about halfway between Mozambique and Madagascar and around 110 km (68 mi) northwest of Europa Island. It is administered by France as part of the French Southern and Antarctic Lands, though it is claimed by Madagascar. The rim of the atoll averages around 100 metres (330 ft) in width and encloses a shallow lagoon of depth no greater than 15 m (49 ft). Overall, the atoll is about 10 km (6.2 mi) in diameter, rising steeply from the seabed 3,000 metres (9,800 ft) below to encircle an area of 80 km2 (31 sq mi). Its exclusive economic zone, 123,700 km2 (47,800 sq mi) in size, is contiguous with that of Europa Island.

Europa Island, in Malagasy Nosy Ampela is a 28-square-kilometre (11 sq mi) low-lying tropical atoll in the Mozambique Channel, about a third of the way from southern Madagascar to southern Mozambique. The island had never been inhabited until 1820, when the French family of Rosier moved to it. The island officially became a possession of France in 1897, though it is claimed by Madagascar.