The land in the middle of Northern Beleriand. In the angle between the Forest of Brethil and Sirion in the West and Mindeb and Forest of Neldoreth in East. The Northern confines of the land was the Encircling Mountains, the Crissaegrim, and Dorthonion. The dry bed of the Dry River divided Dimbar from the Narrow Land to the West and North-West. The crossing of Sirion from Dimbar to the Narrow land was over the ford Brithiach. River Mindeb came from the encircling mountains and divided Dimbar from Nan-Dungortheb in East before it met the eaves of Neldoreth. From Dimbar over the high and sheer walls of Crissaegrim and Ered Gorgoroth into Dorthonion was only one pass; the Pass of Anach who ran besides the wells of Mindeb comming from the highland.