The Rocas Atoll (Portuguese: Atol das Rocas [aˈtɔw dɐs ˈʁɔkɐs]) is the only atoll in the South Atlantic Ocean. It belongs to the Brazilian State of Rio Grande do Norte. It is located approximately 260 km (160 mi) northeast of Natal and 145 km (90 mi) west of the Fernando de Noronha archipelago. The atoll is of volcanic origin and coralline formation.