One of the symbols of Rome is the Colosseum (70-80 AD), the largest amphitheatre ever built in the Roman Empire. Originally capable of seating 60,000 spectators, it was used for gladiatorialcombat.

The list of the very important monuments of ancient Rome includes the Roman Forum, the Domus Aurea, the Pantheon, Trajan's Column, Trajan's Market, the several catacombs area, the Circus Maximus, the Baths of Caracalla, Castel Sant'Angelo, the Mausoleum of Augustus, the Ara Pacis, the Arch of Constantine, the Pyramid of Cestius, and the Bocca della Verità

The historical centre ville is dominated by the traditional "Seven hills of Rome": the Capitoline, Palatine, Viminal, Quirinal, Esquiline, Caelian, and Aventine hills. The Tiber flows south through Rome, with the city centre located where the midstream Tiber Island facilitated crossing.

Large parts of the ancient city walls remain. The Servian Wall was built twelve years after Gauls' sack of the city in 390 BC; it contained most of the Esquiline and Caelian hills, as well as the whole of the other five. Rome grew out of the Servian Wall, but no more walls were constructed until 270 AD, when Aureliano began building the Aurelian Walls. These were almost twelve miles (19 km) long, and was still the wall the troops of the Kingdom of Italy had to breach to enter the city in 1870.

Though relatively small, the old city center contains about 300 hotels and 300 pensioni, over 200 palaces, 900 churches, eight of Rome's major parks, the residence of the President of the Italian Republic, the houses of the Parliament, offices of the city and city government, and many great and well-known monuments. The old city also contains thousands of workshops, offices, bars, and restaurants. Millions of tourists visit Rome annually, making it one of the most visited cities in the world.