Strategically located along historic sailing routes, Cartagena has been colonized by a veritable who’s who of Mediterranean superpowers over the millennia, resulting in a rich and multi-layered cultural heritage, and a history both glorious and turbulent. From atop a hill, Concepción Castle served as a fortress for Carthaginians, Romans, Visigoths, Arabs, and Castilians. The 13th century Old Cathedral stands on the remains of a Roman Theatre just discovered in 1987. More recent architectural contributions include modernist designs of public buildings and private dwellings by pupils of the famous architect Antonio Gaudi.