The ancient Roman port city of Tarragona, on a rocky bluff above the Mediterranean, is one of the grandest but most neglected sightseeing centers in Spain. Despite its Roman and medieval remains, it's merely the second oldest city of Catalonia

The Romans captured Tarragona in 218 B.C., and during their rule the city sheltered one million people behind 64km-long (40-mile) city walls. One of the four capitals of Catalonia when it was an ancient principality and once the home of Julius Caesar, Tarragona today consists of an old quarter filled with interesting buildings, particularly the houses with connecting balconies. The upper walled town is mainly medieval, the town below newer.

In the new town, walk along the Ramble Nova, a fashionable wide boulevard that's the main artery of life. Running parallel with Ramble Nova to the east is the Ramble Vella, which marks the beginning of the old town. The city has a bullring, good hotels, and even beaches. The Romans were the first to designate Tarragona a resort town.
http://www.frommers.com/destinations/tarragona/1176010001.html

Tarragona is a city located 100 km South of Barcelona. The city has been known as Imperial Tarraco since the Roman domination. In Tarragona you can admire some of the best preserved Roman ruins in the Iberian Peninsula.