Torech Gorthaur (Orc."Nâz Gurshaur") was Sauron's Abode in Dorthonion.It was a black Cave in a Mountain towering above the vale of Rivil.Later, after Sauron had been subjugated by Lúthien Tinúviel and Huan he returned to bhis old headquarter ,where he lived as a Vampire for a long time, shunning to be ridiculed by his dark Master.