Worlds of Ultima: The Savage Empire

The Avatar: Not just in Britannia anymore.

Ultima VI leftovers
Savage Empire was, along with Martian Dreams, an effort by Origin to milk the Ultima VI engine for every last drop it's worth. As such, there are some remnants of the earlier game hanging out in the code.

The Realm of the Gargoyles
The Ultima VI engine uses one 1024x1024 global worldmap, and five 256x256 dungeon levels, the fifth being the Gargoyle Realm. Savage Empire only uses the global map, and three of the dungeons. The fourth map has been completely blanked out, however the Gargoyle Realm exists in its entirety! Drawn with SE tiles it is unusable, and this is solely a leftover.

The Avatar's Helmet
The helmet slot from Ultima VI is also unused in this game.

Debug Codes
The alt-codes mentioned on the Ultima VI article also exist here, but unlike that game access has been disabled. It is possible, however, to patch the game executable to regain access.