Angband is the name of a realm once belonging to Morgoth. It was located in the far North of Middle-earth and was the site of Morgoth's fortress, Thangorodrim ('Chain-of-Fanged-Mountains'), during the First Age. The fortress was built after Morgoth stole the three Silmarils from the Elves and destroyed by the Valar at the end of the First Age. Only the frozen Northern Waste remained.
Tyler, J.E.A. The Tolkien Companion. New York: St. Martin's Press, 1976. 15.