Turn of Durin
This tower ruins some is located above the Moria, on the Celebdil. This tower becomes a symbol of the battle baited between the good and the evil at the time of the combat epic which opposes the Balrog to Gandalf after this one fell of the bridge destroyed in the mines of the Moria, drawn towards the bottom by the whip from the Balrog. This combat, that Gandalf ends up carrying while losing the life (and that it becomes Gandalf the White ) is held in top of this tower and at various levels in ruin of which Gandalf and the Balrog slip during their combat.
The tower of Durin was built at the most point of Zirakzigil. It makes party integral of Khâzad Dhum. One reaches it by the staircases without end. Once overcome Balrog, the staircases were to condemn forever.