If you can plan to stay as long as a week, you won't run out of things to do and you'll still feel like you're leaving too soon. But if your time is limited, allow at least four days to see all of Rome's major attractions . If you try to cram the entire city into a two-day span and do nothing but run from place to place furiously snapping pictures, you'll only be cheating yourself. After all, Rome wasn't built in a day and it can't be seen in one, either.