Boirenn: Burren, in the County Clare
Branè: probably a hill not far from Ardee, in the County Louth
Breslech Mor: a fort in Murthemne
Brecc: a place in Ulster
Brega: the eastern part of Meath
Brenide: a river in Conalle Murthemni, near Strangford Lough
Bricriu: son of Carbad, and the evil adviser of the Ulstermen
Bri Errgi: stronghold of Errge Echbel, in the County Down
Brigantia: Betanzos, in Galicia, on the north coast of Spain
Bri Ross: a hill to the north of Ardee, in the County Louth