Fall of Barad-dûr

The utter ruin of Sauron and his stronghold of Barad-dûr, brought about by the destruction of the One Ring. When Sauron first built his Dark Tower in the Second Age (nearly five thousand years before the War of the Ring) he used the power of his Ring to forge its foundations. At the end of the Second Age, he was defeated and the first Barad-dûr was torn down, but it was beyond the abilities of Elves or Men to destroy its foundations. Long afterwards, Sauron rebuilt the tower in the same location, but with the destruction of the Ring, the impregnable foundations failed, and the tower was overthrown.