Cartagena, the new Carthage that outlasted the old one

Around 227 BC, the Carthaginian general Hasdrubal the Fair founded a city on a superb natural harbour on the south-east coast of Spain and named it, in Punic, Qart Hadasht: New City. It was not the first place to bear that name. Carthage itself, the great North African rival to Rome, meant the same thing in the same language a few centuries earlier. The Romans, once they had taken this second New City for themselves, simply Latinised the confusion into Carthago Nova, and the name has settled, over two thousand years, into Cartagena.

Few cities on this coast wear that much history quite so visibly, or quite so far beneath the pavement.

Silver, and the war it paid for

Hasdrubal chose the site partly for the harbour, one of the best natural anchorages in the western Mediterranean, and partly for what lay in the hills around it: rich deposits of silver and lead, worked first by Carthaginian and then, after the Roman general Scipio Africanus captured the city in 209 BC during the Second Punic War, by Roman engineers on an industrial scale. The mines helped bankroll both empires' wars in turn, and Roman Carthago Nova grew rich enough on the proceeds to build a theatre that could seat several thousand people, a scale of public building usually reserved for much larger cities.

That theatre was then, in effect, mislaid for the better part of two thousand years.

A theatre found under a shopping street

Over the centuries, later Cartagena was built directly on top of its Roman predecessor, layer upon layer, until the theatre's exact location had been forgotten entirely. It was rediscovered by accident in 1988, during renovation work on a nearby building, and the scale of what lay underneath took years to establish: a cathedral had been built partly over the stage, and a covered market and a scatter of ordinary houses sat above the rest. Excavation and restoration continued for more than a decade, and the site now includes a museum, designed by the architect Rafael Moneo, that leads visitors down through the later city to the Roman one beneath it.

A navy that never really left

Cartagena's harbour has been valued by whoever controlled it, which is one reason it never entirely lost its military role. In 1888, the Spanish naval officer and engineer Isaac Peral launched an early military submarine here, built with electric propulsion and a torpedo tube at a time when most navies were still working out whether submarines were a serious weapon at all. His vessel is preserved today on the waterfront, a short walk from the Roman theatre, an odd but fitting pairing of two very different kinds of engineering ambition on the same stretch of quay. The city remains home to a working Spanish naval base, the Arsenal de Cartagena, and warships are still a normal sight from the cruise berths.

Several Mediterranean sailings from British ports call here for a day, usually as one stop among several on a longer Spanish or Iberian itinerary, which is enough time for the theatre and a walk around the old town's Modernista buildings, put up when the mining money was still flowing at the turn of the twentieth century.

The mining money left its own mark above ground, too. When the silver and lead seams began to run low towards the end of the nineteenth century, the profits that remained were spent on the wide Modernista buildings that still line the streets near the harbour, wrought iron and glazed tile in the same idiom, roughly, as the more famous examples further up the coast in Barcelona, if on a smaller and less visited scale. Ambassador's Christmas Sun Escape to Spain and Portugal, sailing from Tilbury, calls here between Cartagena's older neighbours Alicante and Almería, which makes for an easy comparison of three quite different Spanish Mediterranean ports in the course of a single fortnight.

Cartagena rarely gets billed as a headline destination, more often a call on the way somewhere grander. That undersells a city that has been fought over, mined, buried and rebuilt often enough to have earned rather more attention than it usually gets.