Durin's Tower was a tower upon the peak of Zirakzigil, above Moria, to the south of the Redhorn Pass. It was here that Gandalf defeated the Balrog known as "Durin's Bane" in the Battle of the Peak.
It was carved by the Dwarves of Khazad-dûm out of the living rock of the mountain, and could only be reached by the Endless Stair which began in the deep far below the mines. During the Battle of the Peak, the tower was destroyed, and the stair was blocked with rubble.