Emerald Shrine

The Hidden Palace shrine in S3&K.

The Emerald Shrine is the resting place of the Master Emerald, and in some cases the Chaos Emeralds or Super Emeralds. It was first depicted in Sonic & Knuckles, as the raison d'être of the Hidden Palace.

Mystic Ruins

Seen in Sonic Adventure, the original Emerald Shrine was located outdoors in Mystic Ruins four thousand years ago, next to the Knuckles Clan's city, and housed both the Master Emerald and the Chaos Emeralds. In Tikal's time it was occupied by the chao, and their watery guardian Chaos. Pachacamac's attack on the Shrine led Perfect Chaos to lay waste to the Knuckles Clan. Using a kind of Chaos Control, Tikal sealed Chaos (and herself) inside the Master Emerald to prevent further destruction; the backlash from this event wrenched half the continent into the sky, Emerald Shrine included. From then on the Shrine existed on Angel Island, and can be visited in the Adventure Field.

Hidden Palace Zone

In the final chapter of the Death Egg Saga during Sonic 3 & Knuckles, Sonic and Tails confront Knuckles at the heart of Angel Island: Hidden Palace Zone, under the Lava Reef volcano. There is a subterranean Emerald Shrine here, with the Super Emeralds installed on flowery plinths and the Master Emerald supported above them. Characters are teleported to this Shrine by hopping into a Giant Ring.

Cannon's Core and the ARK

In Sonic Adventure 2, Sonic and Knuckles are astounded to discover a replica of the Mystic Ruins altar at the heart of the Space Colony ARK. Constructed by Professor Gerald Robotnik, the imitation Shrine is part of the power supply to the Eclipse Cannon, built in Cannon's Core to allow the weapon to tap the Chaos Emeralds. Biolizard was sealed in the core after the G.U.N. attack 50 years ago, and is fought at the base of the shrine by Sonic and Shadow.

Altar Emerald

The short boss level at the end of Sonic Advance 3 is Altar Emerald, another stony, outdoor shrine (resembling the one in Sonic X) which holds only thr Master Emerald. Located amidst the vast, cloudy ruins of Chaos Angel, Altar Emerald sees the game's final fight against Eggman, and Gemerl's twisted transformation into the extra final boss. Knuckles pointedly remains here in the game's end sequence, even as the other characters run off to celebrate.

Sonic Chronicles: The Dark Brotherhood

The Nocturnus Echidnas invade Angel Island during Chapter 5 of Sonic Chronicles. Sonic and Knuckles fight their way across the Island in an attempt to stop Imperator Ix accessing the Shrine; in this game, it is located inside a pyramid-temple. Only briefly seen in a cutscene, the Emerald Shrine holds only the Master Emerald.