Erebor.

A not precisely defined area in Near Eastern Middle-Earth ( See Arda / Endor.) south of Ered Mithrin and Withered Heath. It was west of the Iron Hills and east of Northern Mirkwood.

The Lonely Mountain is placed in Erebor and so is Dale, Esgaroth and the Long Marshes and the Long Lake. From Mirkwood passing Thranduil`s Caverns to the lake ran the Forest River.

South, out of Erebor, into Wilderland and Rhovanion from the Long Lake and the Lonely Mountain runs river Celduin.