Lost Cities of the World ~ Carthage

While the region still exists, not much is left of the ancient seaport which was destroyed not once but twice, first by the Romans during the Punic war in 146BC. But the city rose again to be a Mediterranean trading port before being sacked by the Arabs in 698 AD. The ruins, scattered across Byrsa Hill in Tunisia, can be visited, with part of an aqueduct still visible.

(From the Guardian.com)