The only temple with a Holy of Holies is the Salt Lake Temple. It's a special room adjacent to the celestial room (it's through the locked middle door in between two sealing rooms if you're familiar with the Salt Lake Temple) that only the president of the church and a cleaning lady that's set apart to clean it are authorized to enter. It's an ornately decorated room with a domed sealing and a large stain glass window depicting the First Vision. You can see the outside of the window from the temple sealing office. The Manti temple used to house the holy of holies until the Salt Lake Temple was completed. I hope that helps. BTW, thanks Skippy, for mentioning the Salt Lake Temple tour on my website. I really appreciate the plug.
