Tol Sirion
From Tolkien Gateway
Tol Sirion was the island on the upper reaches of the River Sirion where Finrod Felagund built the tower of Minas Tirith, renamed Tol-in-Gaurhoth (Isle of the Werewolves) after its capture by Sauron. It was called Wizard's Isle in the Lay of Leithian.
