Black Gate
From the One Wiki to Rule Them All, the Lord of the Rings Encyclopedia.
The Black Gate was the common name for the Morannon which was built by Sauron to protect and guard the northern entrance into Mordor. Frodo and Sam had a chance to go through the Black Gate when they arrived at Mordor, but it was so heavily fortified and guarded that they turned away and were led on a different route into Mordor by Smeagol. This gate was so gigantic that Trolls were used to open the gate for incoming Orcs (the size of the gate also kept Frodo and Sam from attempting to pass through it). Orcs were also used to guard the gate at all times. The Morannon was the site of the last valiant battle of the War of the Ring, in which Elessar (Aragorn II) led a large army of about 6000 Men (plus one Elf, one Dwarf, and an Istar) to a last stand against Sauron, and to distract him so as to allow Frodo and Sam to destroy the One Ring in the fires of Orodruin.
Named the Morannon by the Sindarin Elves, its translation was literally "black gate," and it was the main entrance into Mordor. The Black Gate was set in an impregnable black stone and iron wall that stretched from the Mountains of Ash in the north to the Ephel Duath (Mountains of Shadow) in the west. The wall has been estimated to have been 60 feet high and 250 feet long with each half of the great gate being 90 feet wide and set on large stone wheels. Behind the gate were circular stone ramparts, and when the gate needed to be opened, two pairs of Mountain-trolls who were tethered to gigantic beams pushed their way around their rampart's track, gradually levering open the gate. In Gondor's early days, when it was building towers and cities such as Minas Ithil and Cirith Ungol close to Mordor's border, it raised the two great Towers of the Teeth, Narchost and Carchost, which were built on either side of the wall and were tall enough to overlook it. In those days they prevented anything from entering or leaving the black land, but eventually, as with most of Gondor's outposts, the watch failed and they were taken over by the servants of Sauron. Once taken by the Enemy, they became a monument of dread, fear, evil, and awe by anyone who saw the gate.
