Barren world on the other side of the Barrier at the Galactic Center. Pharos was chosen as the place of exile for Zeus, who was imprisoned inside of the brain dead Proteus, and the Hecatonchires were erected to imprison him there.
Pharos was visited by Captain Kirk and the Enterprise-A (Star Trek V: The Final Frontier), where Sybok made contact with Zeus and was chosen as his new host. Sybok/Zeus eventually escaped from Pharos, but was eventually imprisoned in the Hecatonchires (or the Barrier) surrounding it.