Although Rome is a vast place, its metro is relatively small, and it's among the smallest among…read moreEuropean capitals.
The Rome Metro, called Metropolitana di Roma in Italian, is the Eternal City's main medium of public transport. It began its operation in 1955, making it the oldest system of its kind in Italy.
Seeing as it is quite small, navigating the Rome underground is very straightforward. The main thing to remember is that Roma Termini is the connection point between lines and just about every other transport in the Eternal City.
Out of the three lines, only A, which appears red or orange on maps, and B (the blue line) are completed and are the ones that pass through the most landmarks, such as the Vatican Museum, the Colosseum, the Spanish Steps, etc. Line C is a new line gradually being opened in stages.
My partner, our friends, family member, and I used it for 2 days during our stay. A single ride costs €1.50 and is valid for 100 minutes on a combination of metro, buses, and trams. But we bought a €12.50 ticket valid for unlimited metro, bus, and train travel within Rome for 48 hours from validation. It was generally clean and safe; keep one's belongings close and watch out for pickpockets (as one should in most major cities), and one should be fine.