Despite being a very big city, Rome does not enyoy a very well developed subway line system. Currently there are two lines only - Metro A and Metro B and those do not even cover the city centre in full. There are a few interesting projects on the extensions of these lines but nothing has been realized yet.
Therefore, unless you are staying in the rome city centre and can do most of your sightseeing on foot, you might need to catch few buses as Read More....