The Grand Hall, also known as the Grand Hall, is a medium sized zone that can be accessed by the players after acquiring a Mansion Key to unlock sealed mansion doors that connect to the central hall.
While exploring, players are able to see many 'landmarks' that include the following:
- Guttermouth Cells - The Guttermouth Cells can be seen in certain sections of the hall, typically found under the stairs leading to different rooms of The Mansion. These cell doors can only be accessed with the Guttermouth Key. Once obtained, players can enter and partake in different challenges offered in these rooms.
- Ratboy Statue - The Ratboy Statue is the main highlight of The Grand Hall, with the statue 'bracing' the grand halls of The Mansion. The only noticeable thing about the statue is the Rat Tokens that can be found on certain parts of the statue.
- The Theatre's Entrance - The Theatre's entrance can be found on one of the ends of The Grand Hall. This can be identified if the door possesses dull and dark colors. It can only be accessed if the players had acquired a Theatre Key.
- The Vault's Entrance - The Vault's entrance can be found on one of the ends of The Grand Hall. This can be identified if the door possesses bright and 'shiny' colors. It can only be accessed if the players had acquired an Ancient Key.
Harvestables that can be found in the area include Bad Dust, Book of Corrupted Tales, Changing Machine, Clock, Concentration Cube, Crumbling Root, Cursed Cards, Danger Head, Dream Dust, Dream Mushroom, Freedom Cube, and the Plugstack.
Mobs that can be found in the area include Caught Man, Corrupted Gold Knight, Corrupted Onyx Knight, Gold Ogre, Golem Baron, Goon, Macabre Candelabra, Mansion Ant, Monstrosity, Nightmare Lantern, Path Gambler, Running Man, and the Spiker.
Overall, The Grand Halls acts as a "central hub" to redirect players to different areas of The Nightmare. The zones that are connected by The Grand Hall are The Theatre, The Mansion, The Old Mansion, The Vault, and Fish Hall. It also serves as a popular farming spot as many mobs and collectibles can be found in the grand halls.
- The Grand Hall have many doors closed off to the players, presumably places that players are unable to explore.
- The Old Stone Head and the Wise Stone Head NPCs, with dialogue sound effects being one of the loudest and most irritating in Fantastic Frontier; can be found in opposite directions in one of the sidehalls.
- The Grand Hall is a very dangerous place due to the amount of mobs which can spawn, such as the Corrupted Gold Knight, Corrupted Onyx Knight, Macabre Candelabra and more.