Artifacts in Might & Magic VII.

Yes, in The Pit, there are several houses that remain empty throughout the game. It's the hall with lava streams and bridges over them. I think there's also a Temple of Darkness there. Although I don't remember exactly what else is there... it's been a while since I played :smile32:

And I think there are other houses that remain empty throughout the game.

Yes, in Celeste and the Abyss, there are 2 empty houses; most likely, they planned to expand the storyline with two more advisors. Apparently, they weren't just temporary advisors but core advisors. There would probably be intrigues and other things, for example, necromancers who are not happy with Castor's rise to power, etc. It's a pity that they didn't manage to finish many things...