It is formed by the atolls of Marokau to the north (populated by 100 people)[1] and the uninhabited Ravahere to the south.
[2] The two atolls are separated by a 2 km (1 mi) wide sound (geography).
[3] These two neighboring atolls were discovered by Louis Antoine de Bougainville in 1768.
He described Marokau and Revahere as a "chain of islands linked by reefs".
[5] Administratively the Two Groups Islands belong form the territory of the associated commune of Marokau, itself part of the commune of Hikueru, which consists of the two atolls of the Two Groups Islands (Marokau and Ravahere) and the three atolls of the associated commune of Hikueru (Hikueru, Reitoru and Tekokota).