Altar Emerald

Altar Emerald
Normal Final Zone, Sonic Advance 3
Number of Acts: 1
Boss: Gemerl & Hyper Eggrobo

Altar Emerald is found after beating Chaos Angel's boss by moving just a bit further and finding the Final Zone Ring (though, after completing the game, you will be automatically taken to Altar Emerald after beating Chaos Angel). Its similar to Death Egg Zone in Sonic 2 in that instead of a full-length platforming level, the zone is simply two back-to-back boss fights (with rings, this time). Said bosses are Gemerl and Eggman.

After beating Eggman, if Sonic was the lead character and all 7 Chaos Emeralds were collected, the true final zone will appear, Nonaggression. If not, the normal ending will play.

Since the Master Emerald is found here, this area must be located on Angel Island, and presumably represents the same place as the Emerald Shrine in Sonic Adventure.

This zone's name is a bit of a play on words, as the Master Emerald "alters" the separated pieces of the planet, fully reunifying them into a single mass.