Could be anywhere.
When I'm shooting a bride, it's always been during the wedding day so choice of location is limited by a lot of factors, so the ability to find a good spot or make use of what is available, is really key.
I've got a list (mostly in my head) of places around my city that would be good for shooting indoors. Usually big places with lots of windows...
Do you have any indoor gardens? What about fancy hotels or just any building with big grandeur stair cases?
If you can get a location that looks good and has good light, then you are gold. If you can't find a place that looks good, then concentrate on finding spots with good light and focus more on the subject and don't include as much of the surroundings.
You could even use locations that don't look good at all and use that to your advantage for some moody shots. I've seen some great shots of brides in hotel hallways and stairwells. Not to mention a lot of grungy back-alley shots.
Maybe you forget about trying to find good light and just make your own with flash etc.