The ruined town of Baelo Claudia is one of Andalucía's most important Roman archaeological sites. These majestic beachside ruins – with fine views across to Africa – include the substantial remains of a theatre, a paved forum, thermal baths, the market, the marble statue and columns of the basilica, and the workshops that turned out the products that made Baelo Claudia famous in the Roman world: salted fish and garum (spicy seasoning made from leftover fish parts). There's a good museum.
Baelo Claudia particularly flourished during the reign of Emperor Claudius (AD 41–54), but declined after an earthquake in the 2nd century. Live musical performances sometimes happen on July and August evenings.