Utumno.

Udûn. ( Udûn also applies to a valley in Mordor in Third age. )

Melkors first fortress delved deep benieth the dark mountains of Ered Engrin where the light of the Northern lamp Illuin were cold and dim. Utumno is on maps shown to have been slightly further North and West than Angband in later days but if this is just unaccurate maps are hard to determinate. Melkor began the building of Utumno in the Days before Days Valian Year 3400. was laid waste in the Days of the Threes V.Y.1099 ( Utumno lasted for 1149 Valian Years.) during the first war of the Valar shortly after the awakening of the Elves and Melkor was made captive and in the chains of Angainor brought to Aman and inprisoned.

Related Links.: Misc.: Reckoning of the Years. Battles.: War of the Gods.