J.R.R. Tolkien > The Silmarillion >
There is also a another Minas Tirith from Tolkien's works, that appears in the Silmarillion. It was also a great watchtower built by Finrod Felagund between Dorthonion and the Ered Wethrin at the island of Tol Sirion, to guard the entrance to the Pass of Sirion, which was one of the ways into Beleriand from the lands under the dominion of Morgoth, helping to hold the Siege of Angband. After the construction of Nargothrond was completed further down the river Sirion, Felagund left the Tower and its surrounding lands under the control of his brother Orodreth.
After the Dagor Bragollach, most of the defenses erected by the Noldor against Morgoth's forces were overwhelmed, but the Pass of Sirion held out for more than two years after the initial devastating assault, as the power of the Vala Ulmo dwelt in the waters of the river, and Minas Tirith was highly defensible and Orodreth a strong and stalwart warden.
However, he was not strong enough to face Sauron. Sauron came to the fortress, and with his great power caused a cloud of fear to descend upon the garrison, and while Orodreth fought valiantly he was no match, and he was driven from Minas Tirith. Sauron then turned it into a watchtower for Morgoth, a stronghold of evil, and the once beautiful island of Tol Sirion became a place of terror, and was thereafter known as Tol-in-Gaurhoth, or Isle of Werewolves. Nothing could go through the Pass of Sirion without Sauron's knowledge, and now holding all of the entryways into Beleriand Morgoth could attack the Noldor and their allies at whim.
Minas Tirith dominated by Sauron was the setting for two major scenes in the saga of Beren and Luthien. Beren son of Barahir along with Finrod Felagund and ten companions took this dangerous road on the quest to take a Silmaril from the Iron Crown. They were discovered, and while the duel of Sauron Gorthaur and Finrod Felagund was long and hard, he too was no match, and they were taken captive to the dread prisons beneath the Tower. Sauron was determined to learn what their mission was that brought them there, and after dreadful torture one of them would be devoured by werewolves, as they would reveal neither their identities nor their mission.
A shadow of fear fell across the heart of Lúthien Tinúviel at that moment, and Melian told her that Beren and Felagund were captured without hope of rescue. She then decided to do what she could to rescue them herself, as no one else would do so. She was hindered both by her father Thingol and the two perfidious Sons of Fëanor Celegorm and Curufin, but she managed to overcome these obstacles and with the aid of Celegorm's hound Huan, arrived at Tol-in-Gaurhoth.
There, she attracted the attention of Sauron, who attempted to take her captive, but Huan saved her, and because not even Sauron could thwart Huan's destiny, they managed to overcome him, and gain control of the Tower. She cast the spell that unbound stone to stone, and the tower was destroyed, and the pits and dungeons laid bare. Unfortunately this rescue came a little too late to save the tower's builder. As a werewolf was about to devour Beren, Finrod Felagund leaped in its way and was slain.