Cartagena, Spain
Founded by Carthaginians circa 220 BC, Cartagena has one of the world's oldest naval bases and a wealth of Roman archaeology. The 1st-century Roman theater was only unearthed a few decades ago, and discoveries are ongoing, including an entire town block dating to Roman times called the Barrio del Foro Romano. Likewise of interest are the Casa de la Fortuna – a house with Roman murals, mosaics and excavated objects – and the Punic Wall Interpretation Center displaying remains of a 3rd century defensive wall.