When the Roman city of Tarraco converted to Christianity, its people began burying their dead beside the Francolí river, west of the town, and the necropolis that grew up there over the fourth and fifth centuries is now one of the most important early Christian burial sites in the western Mediterranean. Hundreds of tombs were found, from simple graves to carved marble sarcophagi, along with remains of a basilica. Tradition links the site with Saint Fructuosus, the bishop of Tarraco burned in the amphitheatre in the year 259 along with two deacons.
The site was found in the 1920s during construction of the tobacco factory next door, and it has its own museum, part of the National Archaeological Museum of Tarragona; check whether it is open, as access has varied over the years with restoration work. The whole ensemble of Roman Tarraco is a World Heritage Site, and Tarragona makes it easy to walk from monument to monument.
Riding into Tarragona is coastal city riding, with traffic, roundabouts and port traffic near the Francolí, but parking a bike is easier than parking a car. Once you have seen the amphitheatre by the sea, the circus vaults, the walls and the old town around the cathedral, head out to the Pont del Diable, the Roman aqueduct a few kilometres north, which you can walk across. Inland, the roads climb into the Priorat and the Montsant, with tight, scenic bends through terraced vineyards.
Tarragona has a fishermen's quarter, El Serrallo, where restaurants serve the day's catch and the local sauce, romesco, made with dried peppers, almonds and garlic. In late winter and spring, calçots, grilled spring onions dipped in a romesco-style sauce, are the regional obsession around Valls, just inland. Human towers, castells, are another Catalan tradition with deep roots here, and the city hosts major competitions.
Fuel and services are plentiful throughout the city and in Constantí and La Canonja nearby, though La Canonja borders the petrochemical complex, which is not much to look at. Summer is hot and humid on the coast, and spring and autumn are ideal. Watch for the many speed cameras on the main roads around the city.