Sidi Bou Said is a village east of Tunius, the capital of Tunis, easily reachable by light rail. It’s a sparkling white and blue village right at the Mediterranean sea, with great views of the coastline and the sea.
Carthage is an ancient kingdom, the archenemy of the Roman republic. Three wars were fought until the Romans finally conquered Carthage in 146 BCE, long before the Roman Empire. There is essentially nothing left of Carthage except an overgrown cemetery. The Romans were quick to raze everything and build their own villas, an amphitheater, and a huge Roman bath right at the sea.