Towers of the Teeth

Two towers, called Carchost and Narchost, that stand on either side of Cirith Gorgor, the Haunted Pass, which lay between the Ephel Dúath, the (western) fence of Mordor, and the Ered Lithui, the (northern) Mountains of Ash, at the northwest corner of the land of Mordor. Frodo, Sam, and Gollum beheld these towers and the Morannon, the Black Gate, between them as they debated the best way to enter Mordor, and it was below these towers that the Captains of the West and their small army made their last stand against the forces of Sauron.

Originally built by men of Gondor following the downfall of Sauron at the end of the Second Age, the Towers of the Teeth were eventually abandoned by them and were taken over by the servants of the Dark Lord. They were then repaired and fortified and were incorporated into the defenses of the pass and gate.

There are no definitive records to this effect, but some say that Carchost, which means "fang fort" in Sindarin, stood on the east (or north) side of the Morannon and Narchost, which means "fire fort" in Sindarin, stood on the west (or south).