Hithlum is the region north of Beleriand near the icy Helcaraxë. It was separated from Beleriand proper by the Ered Wethrin mountain chain, and was named after the sea mists which formed there at times: Hithlum means Mist-shadow. Hithlum was subdivided into Mithrim, where the High Kings of the Noldor had their halls, and Dor-lómin, later a fief of the House of Hador. Hithlum was cold and rainy, but quite fertile.