This is one of the most significant archaeological sites in Tunisia. Founded by the Phoenicians in 814 BC, Carthage was
the dominant city-state in the area for nearly 700 years. After the Romans conquered the city in 146 BC, they destroyed it. Most of the ruins you'll see there today date from the period of Roman rule.
The archaeological zone is spread out over a large area—half a day is the minimum amount required to cover the entire area. The National Museum of Carthage on Byrsa Hill is a good place to start. The museum's exhibits and the panoramic view from the hill provide a good orientation to the site. Also visit the Roman baths, the amphitheater, the Antiquarium, the Punic port and the Tophet of Salammbo.
Carthage is a very easy day trip from Tunis. Take the light-rail system and get off at the Carthage Hannibal TGM station, the stop closest to Byrsa Hill. There are other stops near the various ruins, so you can use the train as an alternative to walking. If you're going in July or August, attend the international arts festival. Also in the area is a World War II U.S. military cemetery. 5 mi/8 km east of Tunis.