Utumno, also known as Udûn, is a fortress in J.R.R. Tolkien's Middle-earth, located in the far north of the world during the First Age. It was the first and greatest stronghold of Melkor (later known as Morgoth), the dark enemy of the world. Utumno was a vast, underground complex filled with dark tunnels, pits, and chambers of horror, where Melkor bred monstrous creatures and corrupted the world. It was a place of shadow and cold, surrounded by icy wastes. Utumno's influence spread terror and blight across Middle-earth until it was destroyed by the Valar during the War for the sake of the Elves.