Morannon

The Morannon closes Cirith Gorgor, the Haunted Pass into Mordor. Two sheer hills thrust forward from the mouth of the defile, and on them stand the Teeth of Mordor, two towers strong and tall, Narchost and Carchost: works of the Men of Gondor, built in their pride and power after Sauron's overthrow and flight, lest he seek to return. Beneath the hills the stone is riddled with caves past counting, and orcs lie in them, and no one passes the Teeth without feeling their bite unless Sauron summons him or he knows the passwords that open the gate. Frodo and Sam saw the two vast iron doors and turned aside; the Host of the West came before them from the north-west at the end, and there they were surrounded on the slag-hills while the Ring went into the fire.