A city of the Pheonician and Punic periods from the C6th BC it was the base of a powerful trading empire spanning the entire south Mediterranean and home to a population of the order of half a million people. Its most famous general was Hannibal who crossed the Alps to battle with the Romans. Hannibal suffered his first significant defeat defending the city against Imperial Rome in 146BC and it was completely destroyed. The site was developed by the Romans a century later and Carthage became the capital of the Roman province of Africa. A UNESCO World Heritage List site.
Take the TGM light rail line from Tunis to Carthage-Hannibal station.
Walk. The area is large and sightseeing is sweaty work on a hot day.
Very little remains of Carthage today, and Punic Carthage in particular was completely obliterated.