Barad-dur

There was also a large mining pit that uses prison labor as a punishment for disobedient orcs. There was also a massive forge here too. Which means production of war materials could continue even if under attack.   But its main purpose was the same as any other fort. It provided a secure base of operation able to withstand powerful sieges. The one time Barad-dur was attacked, it took 7 years to defeat. While there is some debate about how literal this is in the books, in the movie the Eye of Sauron is an actual massive eye made of flame. It uses the top of the tower to get an impressive view of the surrounding area. Essentially, this meant that Barad-dur was the central point from which all command and control activities of Mordor's military were centered.

The main modification that Sauron made after construction got started was connecting the foundations to the One Ring. Nice little metaphor for Sauron himself. Without destroying the One Ring, it did not matter what else happened to Barad-dur. It could not be totally destroyed or permanently disabled. But if the One Ring was destroyed, it does not matter how good anything else is going. The foundation is gone and with it Sauron and Barad-gur.

The general aesthetic is meant to be exaggerated Gothic. Basically everything here is meant to be massive and black. The best example of this is the 4,593 foot tall tower that forms the keep. The walls look extremely tall though I have no numbers for them. While I can’t see machicolations or details of the battlements, what looks like the sheer height of the walls makes climbing them the hardest to do for any fort in Middle Earth. In fact, the towers were said to be obscured by clouds. Inside there were large courts accessible via "gaping" gates. The building materials were described as iron, steel or adamant. Which means that it is likely to be the same material as Isengard. There is also descriptions of brick and grey stone used.   Oh, and there is a moat here. Filled with lava. Not only is there a drawbridge (I think it is a drawbridge – could be a normal one), there are gatehouses on either end of it and huge flanking towers on the inner gatehouse. This bridge was described as vast and made of iron. Given that it is over impassible terrain and is impressively long, making it a drawbridge would be merely an added bonus. It seems unlikely that it would be essential for defense.   Tolkien, J.R.R. (1979). "Picture 30: Orodruin and Barad-dûr". In Tolkien, C. (ed.). Pictures by J.R.R. Tolkien: Foreword and Notes by Tolkien, C. (1979 (Hardback) ed.). London: George Allen & Unwin. ISBN 0047410035.

Sauron first occupied Mordor in 1,000 of the Second Age, he began construction of Barad-dur. This lasted until 1,600 of the Second Age. This was when the One Ring was made and used to reinforce the fort. Then the Last Alliance of Men and Elves came. After forcing their way into Mordor, they laid siege to Barad-dur from 3434–3441 of the Second Age. The partial victory allowed for most of Barad-dur to be destroyed. But the foundations remained, which allowed for a rapid rebuilding process later.   Fast forward to the Third Age. Gondor had declined enough that Sauron was able to move back to Mordor. Plus, he had been discovered in and kicked out of his covert base in Dol Goldur. So, in 2951 the rebuilding process began. During this period, the tower became the home to the "Eye of Sauron". But, the whole fort was violently destroyed with the One Ring. With it, one of Mordor's most impressive military assets.