The Washington Post today carried this extensive story on excavations at Butrint, a city in modern Albania that was once a major crossroads of the Mediterranean:
The scope of Butrint's past excites archaeologists of many periods. It was "Troy in miniature" in Virgil's "The Aeneid"; legend says the city was founded by Trojan exiles, but that belief is not supported by archaeological evidence.
Remains apparently run from 750 BC right through the medieval period. The city was eventually abandoned in the 15th century, so preservation is quite good. As with any really huge archeology site, it's going to be the work of centuries to completely excavate the site.