The Sydney State Theater is probably one of the most beautiful decorated building in Sydney. I've never been inside for a concert or a play but they have a tour of the theater and I think I might book in one day to visit the whole places. I definitely need a tripod and a fish eye lens.
Check out the State Theater website for a guide tour, I think it's worth the money. Better still visit it during a concert and you don't pay much more and you get the whole experiences of in a theater when a something is on.
This was shot handheld using a HDR techniques, the image stabilizer on the Panasonic 12-35mm f2.8 is really impressive. I can basically go to any building without needing a tripod. But it's still better with a tripod anyway. You lower your ISO and get less noisy photos.