I have a five-hour layover at FCO on an upcoming Sunday afternoon/evening (departing at 2130h). Having never been to the city, I am tempted to get out and try to see a little bit.

Anyone have suggestions for places to see, things to do, or (especially!) things to eat? I plan on going back in the spring for a few days with someone else, so it isn't important to cram in a bunch of sightseeing. I just hate to waste five hours there by sitting in the AZ lounge eating blister-packed cookies.

I'll have a couple of carryons with me that I'd like to leave in the airport someplace if I can, and then just set out by taxi or train for a little adventure.