There is a fantastic exhibition about Augustus, the founder of the Roman Empire, at the Scuderie del Quirinale which marks 2000 years since his death. Taking photos was prohibited, which was a good because there were a lot of people and it meant that everyone just concentrated on looking at the exhibition rather than trying to get the best shot.
The walls along the stairway out of the Scuderie were glass and there were great views across the rooftops of Rome.