|Hidden Palace Zone|
|Name||Hidden Palace Zone|
|Franchise||Sonic the Hedgehog|
Hidden Palace Zone is the fifth Zone in Sonic & Knuckles (and the eleventh of Sonic the Hedgehog 3 & Knuckles). As the shortest Zone in the game, it consists of a single act and functions as a transition between Lava Reef and Sky Sanctuary. It is also the only Zone in any of the Sega Mega Drive-era Sonic the Hedgehog games that is devoted to plot progression. It is based on a deleted Zone from Sonic the Hedgehog 2; although, that is considered a separate location as it would have likely been located on West Side Island (as the 2013 mobile re-release of the game reveals).
Sonic & Knuckles
In Sonic's storyline (which can also be played as Tails in the lock-on Sonic the Hedgehog 3 & Knuckles), Sonic arrives in Hidden Palace Zone within the Lava Reef Zone. He encounters Knuckles the Echidna, who still believed Robotnik's claims that Sonic is bad, and there is a boss battle in which the two fight each other. The room of the boss battle is particularly notable for the prophetic mural in the background, presumably created by the defunct Echidna society, which foreshadows the final battle between Doctor Robotnik and Super Sonic in The Doomsday Zone.
After Sonic wins, a cutscene is shown in which Robotnik steals the Master Emerald from the Emerald shrine, thus revealing his true intentions to Knuckles, who, in turn, tries to stop him. Knuckles gets electrocuted, and Robotnik is able to get away without any further resistance. The floor then crumbles beneath the characters, sending them plummeting to a lower level of the palace. When Knuckles recovers, he leads Sonic to a teleporter, which transports them both to Sky Sanctuary Zone. There is no Act clear screen at the end of either version of this Zone.
In Knuckles' storyline, the level is much shorter. It contains no enemies or obstacles, and no other objects besides the teleporter used to teleport to Sky Sanctuary, the final Zone in the game for Knuckles (which, again, is much shorter).
The Hidden Palace Zone also appears throughout the second half of Sonic the Hedgehog 3 & Knuckles (after the beginning of the Mushroom Hill Zone), when the player collects one of the Super Emeralds. After entering the first Special Stage after completing the Launch Base Zone, a cutscene is shown in which any collected Chaos Emeralds are transported to the Hidden Palace Zone's Emerald shrine and transformed into Super Emeralds, although they have lost power and are grey. Jumping on a greyed-out Emerald will transport the player to that Emerald's special stage, the completion of which will grant the player a Super Emerald and turn the greyed-out Emerald into its original bright color.
- The only way to get the Gold Brick is to collect all seven emeralds. By completing the Sonic Dimensions level.
- When players first time enter the area, Dr. Eggman will fly in through a secret passage noticing that you haven't collect all emeralds yet and fly out the zone.
- When players do manage to collect all the emeralds and complete the puzzle, Eggman will fly in and steal the Master Emerald, but accidentally break it and fly out after realizing his mistake.