Deep in the Iron Mountains lay the dark fortress of Angbad (Sindarin for 'Hells Of Iron' literally meaning Iron Prison.)The Fortress of Dark Enemy(Morgoth) Located in the dark lands of Dor Daedeloth north of Beleriand created by Morgoth to ward of any attacks from Aman by the Valar and placed Souron as its Commander. But the Valar's attack suceeded in destroying Utumno completely and Captured Morgoth. But Angbad was only partially destroyed after the Valar's attack was mainly upon Utumno and over time the minions and servants of Morgoth who had survived bgan to gather in the ruined pits of Angbad awaiting their masters return.
After 3ages of imprisonment Morgoth descended upon Middle-Earth again using Angbad as his keep , he raised the volcanic Thangorodrim over the fortress as its protection he dwelt there until challenged by the Elven king Fingolfin to single combat. Morgoth then reighned over his fortress till the end of the first age when it was destroyed in the war of wrath by the Valar and Morgoth taken away in chains and cast into the void.
By Jordan Yates