River, Northern Territory , Australia.
It flows east to Limmen Bight on the Gulf of Carpentaria ; it is about 325 mi (525 km) long and is navigable for about 90 mi (145 km). It marks the southern limit of the region known as Arnhem Land . North of the river's mouth is the "Ruined City of Arnhem Land," a region of sandstone whose weathered shapes suggest ruined buildings.