So, I'm sure many of you remember this place from Murkmire DLC:
It's still one of my favourite places in all of ESO, even though you only get to see it once per character. Since the assets for it are already all there, I was wondering... perhaps there should be a house based around this idea of an ancient ayleid portal nexus located on a small demiplane? The thing that would make it unique, though, is that because of the portals it could technically function similarly to how Ragnthar does in the Fighter's Guild questline: unbound to any one location. It might be possible to have multiple entrances from different maps, all opening into the same house instance where you'd have exits to different places located in different areas of the house. In its simplest form it could even be one of the open house areas without structures beyond a flat plane circled by portals, thereby allowing players to build their own designs as they wish.
Not sure how feasible it would be, just a thought that popped into my head so I thought I'd share it for fun.