Unrevisitable area

Unrevisitable locations are locations in Final Fantasy games that are inaccessible after a certain point. Such locations may contain items or accessories that can be missed. The first game to have unrevisitable locations is Final Fantasy II.

Final Fantasy IV
In Final Fantasy IV, there are three unrevisitable locations: the Tower of Zot, the Tower of Babil, and the Giant of Babil.

Final Fantasy VI
In Final Fantasy VI, after the Cataclysm, the party cannot return to the World of Balance. This causes several locations to become inaccessible, including Vector, Mt. Kolts, Returner Hideout, Lethe River, Baren Falls, Esper Caves, Phantom Forest, Serpent Trench, and Crescent Mountain Cave. Furthermore, the Imperial Camp, Phantom Train, Magitek Research Facility, Cave to the Sealed Gate, Floating Continent, Burning Home, Crumbling Home, and Dreamscape also become inaccessible once they have been completed.