It was located in the Tantalus Spiral. Moldox was located near the Eye; in its sky time winds coming from the Eye were visible. The Doctor often visited the Eye, finding it beautiful, particularly during his fourth and eighth incarnations.
During the Last Great Time War, the Daleks harnessed energy from the Eye to create a Demat weapon capable of wiping Gallifrey from history. This plan was stopped by the War Doctor, who used Borusa's unique characteristics to harness power from the Eye and wipe all Dalek presence away from the area. (PROSE: Engines of War)