Land of Shadow
Three sides of Mordor were bounded by mountain ranges, arranged in a rough rectangle: Ered Lithui, translated as ‘Ash Mountains’ in the north, Ephel Duath, translated as ‘Fence of Shadow’ in the west, and an unnamed (or was possibly still called Ephel Duath) range in the south. In the northwest corner of Mordor, the deep valley of Udun formed the region’s gate and guard house. That was the only entrance for large armies, and was where Sauron built the Black Gate of Mordor, and later where Gondor built the Towers of the Teeth. Behind the Black Gate, these towers watched over Mordor during the time of peace between the Last Alliance and Sauron’s return. In front of the Morannon lay the Dagorlad or the Battle Plain.