The Tower of Cirith Ungol is a significant location in J.R.R. Tolkien's legendarium, particularly in *The Lord of the Rings*. It is situated at the pass of Cirith Ungol, near the land of Mordor. The tower serves as a watchtower and a stronghold for the forces of Sauron, guarding the entrance to the dark realm. The tower is known for its grim and foreboding presence, symbolizing the power of Sauron and the dangers that lie within Mordor. It is also the site where the character Frodo Baggins is captured by Shelob, a giant spider, during his quest to destroy the One Ring.