Black Gate of MordorBlack Gate of Mordor - "This was Cirith Gorgor, the Haunted Pass, the entrance to the land of the Enemy.  High cliffs lowered upon either side, and thrust forward from its mouth were two sheer hills, black-boned and bare.  Upon them stood the Teeth of Mordor, two towers strong and tall.  In days long past they were built by the Men of Gondor in their pride and power, after the overthrow of Sauron and his flight, lest he should seek to return to his old realm.  But the strength of Gondor failed, and men slept, and for long years the towers stood empty.  Then Sauron returned.  Now the watch-towers, which had fallen into decay, were repaired, and filled with arms, and garrisoned with ceaseless vigilance.  Stony-faced they were, with dark window-holes staring north and east and west, and each window was full of sleepless eyes.  Across the mouth of the pass, from cliff to cliff, the Dark Lord had built a rampart of stone.  In it there was a single gate of iron, and upon its battlement sentinels paced unceasingly." ~The Two Towers, Book IV, chap. 3 (The Black Gate is Closed)