Hithlum is the region north of Beleriand near the Helcaraxë. Hithlum was separated from Beleriand proper by the Ered Wethrin mountain chain, and was named after the sea mists which formed there at times: Hithlum is Sindarin for "Mist-shadow"; its Quenya counterpart is Hisilómë. The Ered Wethrin ("Mountains of Shadow") formed the southern and western wall, and had only a few passes; as such they formed a natural defensive line. The eastern wall was formed by the Ered Lómin or "Echoing Mountains", which curved north-westward to Helcaraxë.
