Pandaemonium is an arena in Final Fantasy Dissidia. It is the representative arena of Final Fantasy II. It consists of a maze-like structure with lots of walls and holes.
In the Dynamic version spike traps cover the half the map and alternate sides after a period of time. Spikes are only active if a player is located on or above the effective area. Damage dealt by the spikes is % based (you cannot be broken by one). Damage dealt by spikes is added to the Brave Pool.
The dynamic version can be bought at the PP store under the system section after beating Shade impulse.
In Final Fantasy II, Pandaemonium was the castle capital of Hell, which the The Emperor raised after he gained demonic powers. It served as the final dungeon, where Firion and company defeated the Emperor once and for all.