Carthago Nova

Stand still for a moment and listen. Gulls call over the harbour, and a breeze off the Mediterranean carries salt into the narrow streets. Under your feet, the pavement covers something much older. Here in Cartagena, the modern city sits directly on top of an ancient one. Shops, flats and church walls rest on Roman streets and Carthaginian foundations. The ancient city has a name that tells you almost everything. Carthago Nova. New Carthage.

That name is a translation. The first founders called this place Qart Hadasht, which means simply "New City" in their Phoenician language. Those founders came from Carthage, the great trading power in what is now Tunisia. In the late third century before Christ, a Carthaginian general named Hasdrubal established a settlement here. He chose the site carefully. It was a peninsula, ringed by hills, with a deep natural harbour on one side and a shallow lagoon on the other. It was a place that was easy to defend and easy to supply by sea.

Ancient writers describe the city sitting among five hills. You can still feel them as you walk. Streets climb suddenly, then drop, then climb again. Some of those rises are now crowned by a castle, a park, or the ruins of an old cathedral. The lagoon that once protected the northern side is gone, drained and built over long ago. But if you stand on high ground and look inland, you can picture the water that once wrapped around this rocky shelter.

Why did Carthage want this spot so badly? Part of the answer lies in the hills behind the city. The mountains around Cartagena held rich deposits of silver and lead. Silver paid for armies, and Carthage needed armies. In the decades after its founding, New Carthage became a key base for the Carthaginian presence in Iberia. This was the power structure that produced Hannibal, the general who later crossed the Alps with elephants to attack Rome itself.

And so the city became a target. During the Second Punic War, in 209 BC, a young Roman commander named Publius Cornelius Scipio led an assault on New Carthage. The Greek historian Polybius tells the story. Scipio learned that the water in the lagoon dropped at certain times. While his troops attacked the main walls, a smaller force waded through the shallows and climbed the defences from the side nobody expected. Here is a detail many visitors miss — Scipio reportedly told his men that the sea god Neptune had promised him help. When the water fell away, it looked like a miracle.

The capture was a turning point. New Carthage held treasure, supplies, and hostages from Iberian tribes. Losing it was a serious blow to Carthage. Scipio went on to further victories and eventually earned the name Africanus. The city, meanwhile, changed hands for good. From this moment, the story of Carthago Nova becomes a Roman story — though the Carthaginian stones did not disappear.

You can still see some of them. Near the old lagoon side of the city, an interpretation centre protects a section of the Punic wall. Punic simply means Carthaginian. The wall is built as two parallel faces with chambers between them, a design used for strength and for storage. Standing beside it, you are looking at defences from the time of Hasdrubal and Hannibal. It is one of the rare places where the Carthaginian city becomes something solid that you can stand next to.

Under Roman rule, Carthago Nova grew into a prosperous colony. The mines kept producing. The harbour kept trading. The city also became known for garum, a strong fermented fish sauce that Romans loved and shipped across the empire. Imagine the smell of the salting works on a hot afternoon. It was not delicate. But it was profitable, and that money helped pay for public buildings, temples, and paved streets.

The greatest of those buildings stayed hidden for centuries. In 1988, workers digging near the ruined cathedral of Santa María la Vieja found remains of a Roman theatre. As excavations went on, a full theatre emerged from under houses and the church itself. It dates from the time of the emperor Augustus, at the end of the first century before Christ. Inscriptions connect it to Gaius and Lucius Caesar, the emperor's grandsons and chosen heirs. Today a museum designed by the Spanish architect Rafael Moneo leads visitors through tunnels and galleries, until the curved seating opens up in front of you.

That theatre is the second surprise of this city. For hundreds of years, people prayed, lived and worked on top of it without knowing it was there. Later builders even reused its stones. When you look at the seats, you can see where the medieval cathedral cuts directly into the Roman structure. Two worlds overlap in a single view. It is a clear picture of how Cartagena grew — layer on layer, each era building on the bones of the last.

The Roman city reaches well beyond the theatre. Around the old forum area, excavations show a street grid, the base of public buildings, and remains of houses. One of them, known as the House of Fortune, keeps traces of painted walls and mosaic floors. You can also find a stretch of the decumanus, a main Roman street, with its large paving stones still in place. Walk slowly here. These were the streets where merchants, sailors and miners once crossed paths every day.

Carthago Nova never fully vanished from memory. Later, in the Roman province system, it became an important regional centre. Its name was shortened over time, and Carthago became Cartagena. Every year, the modern city also celebrates its double heritage in a festival of Carthaginians and Romans, usually in late summer. Local groups dress as soldiers, priests and citizens, and they re-enact the founding and the siege. It is history played as street theatre, loud and cheerful.

Before you move on, look around once more. Notice the hills that shape the skyline. Notice the harbour, still deep and still busy, where naval ships rest today. Then look down at the ground under your feet. Somewhere beneath the stone and asphalt, more of the ancient city is probably still waiting. As you walk away, take a glance at each slope and each old wall. New Carthage is not only behind glass. It is the shape of the city all around you.