The Temporal Tower is a restriction-free dungeon in Pokémon Mystery Dungeon Explorers of Time and Darkness and Pokémon Mystery Dungeon Explorers of Sky. It is the domain of the legendary Pokémon, Dialga and is the final dungeon in the game's main story. The collapsed variant of the tower can be explored once by players In Pokémon Mystery Dungeon Explorers of Sky during the special episode In the Future of Darkness as Grovyle.
The only way to gain access to this dungeon is to obtain transport to Hidden Land by speaking to Lapras who can be found at Treasure Town Beach. The player must then negotiate their team through Hidden Land in order to reach Temporal Tower.
Temporal Tower is a dungeon with 24 floors (25 including the pinnacle) and has a relay point on the 13th floor. The player can expect to encounter a variety of Steel types with the exception of Solrock and Lunatone as well as several Dragon types. When playing as Grovyle in the special episode In the Future of Darkness, players will be confronted by mainly Ghost, Psychic and Poison types. When playing the normal main-game dungeon, the legendary Pokemon Deoxys can be found between the 5th and 10th floors provided that the player has either a Secret Slab or Mystery Part in their toolbox. Aside from Deoxys, none of the Pokemon in Temporal Tower are recruitable.
The boss of this dungeon during the main story is Primal Dialga (not recruitable) and Dialga during the post story. Both are level 45 Pokémon and have been considered by players to be particularly difficult to defeat due to their punishing movesets. Dialga is the only Pokémon in the dungeon, aside from Deoxys, that is recruitable. It is notable for having a 100% recruit rate and will instantly join the player's team after it is defeated in the post story.