The Roman Forum and the Coliseum are at the top of everyone's must-see list for Italy. But the charm and fascination of the ancient world do not stop there. No matter where you are in the center of The Eternal City, you will see remnants of its former glory. Often you'll need to look down, several feet below the sidewalk, to see the ground upon which the emperors and their slaves trod long ago. There you'll spot marble toes and limestone doorsills and brick pavements (which sit above the remnants of the city's underground heating system) and so many more reminders that Rome is a layer cake of civilizations! Here are a few photos of ancient Roman remains -- keep on the lookout as you roam the modern streets, for you will find many, many more on your own Imperial scavenger hunt.