Barad-dûr is the dark fortress where Sauron dwells in J.R.R. Tolkien’s Middle-earth.
The name Barad-dûr means “Dark Tower” in Tolkien’s invented Black Speech. Sauron built the fortress in Mordor during the Second Age, using the power of the One Ring to strengthen and preserve it. It stood near Mount Doom and served as the main center of his power.
Barad-dûr was destroyed at the end of the Second Age when Isildur cut the One Ring from Sauron’s hand, but it was rebuilt during the Third Age. In The Lord of the Rings, the fortress dominates the landscape of Mordor and represents Sauron’s military and spiritual authority.
It is distinct from Orthanc, the tower of Isengard, and Minas Morgul, the former Minas Ithil. Dol Guldur was another fortress associated with Sauron, located in southern Mirkwood.