I just got back from a visit to Rome with my family. We hired a tour guide who decided to detour while on our way to the Colosseum. We drove to the Piazza dei Cavalieri di Malta on Aventine Hill near the Circus Maximus. The piazza was completely empty except for a couple and their cab driver. Our guide said "We have some extra time and I brought you here to see something magical. Go to that door and peer through the keyhole. Don't tell any of us what you see. Let everyone see your reaction." Needless to say there were plenty of oohs and ahhs and even a few cools. I won't disclose what we saw but just do a web search for "Knights of Malta Rome keyhole"