Beneath the streets of Porto Torres sleeps a Roman city. Turris Libisonis, Rome's first colony in Sardinia, founded in the 1st century BCE, prospered here thanks to wheat and maritime trade. The modern town, now one of the gateways to northern Sardinia with its ferries and industries, looks unremarkable at first; yet it rewards those who scratch the surface. Ships dock in the commercial basin, and the centre can be reached on foot in about fifteen minutes along Corso Vittorio Emanuele.

The Basilica of San Gavino, a Romanesque masterpiece

At the top of the Corso stands the main reason for the port call: the Basilica of San Gavino, the largest Romanesque church in Sardinia, built in the 11th century by the judges of Torres. Its silhouette is surprising, with an apse at each end and no main façade. Inside, a forest of reused ancient columns supports the nave; in the crypt lie the relics of the martyrs Gavinus, Protus and Januarius, executed under Diocletian, to whom Sardinians show steadfast devotion. The golden limestone, the cool shade and the silence make this stop a moment of real intensity. Every spring, the Festha Manna, one of Sardinia's oldest festivals, brings the region together around the three martyrs, with processions and songs.

Turris Libisonis, the city below

Heading back down toward the sea, the archaeological park and its Antiquarium reveal the Roman colony: baths decorated with mosaics, paved streets and warehouses of the ancient port. Right next door, the Ponte Romano spans the Riu Mannu with its seven arches, a 1st-century structure that carried road traffic until recent times. The full visit takes barely two hours and gives the modern town an unsuspected depth: you are literally walking on twenty centuries. Following the shore eastward, the little cove of Balai and its church set on the rocks offer a swimming break popular with locals, within walking distance of the centre.

Asinara, the island of white donkeys

If your port call stretches over a full day, the open sea beckons. Facing the coast, the island of Asinara, long a penal colony and therefore spared from any tourist development, has become a national park. Boat or launch excursions reach its clear-water coves, including Cala Reale and its former quarantine station; on the island, you get around by little train, guided vehicle or bike among the maquis, old prison buildings and deserted beaches. The island's stars: its albino donkeys, unique in the world, which graze freely. Check schedules before setting out, as the round trip takes up most of a day.

A Sardinian break

Back in town, the trattorias of the centre serve no-frills seafood: Catalan-style octopus, spaghetti with sea urchins in season, pecorino and carasau bread, washed down with a crisp Vermentino. The squares along the Corso, lively in the late afternoon, lend themselves to a farewell espresso while residents take their passeggiata. Food lovers often leave with a bag of carasau bread or a piece of aged pecorino.

Casting off

Porto Torres has neither the reputation of Alghero nor the lustre of the Costa Smeralda, and so much the better: the port call is enjoyed without crowds, between a thousand-year-old basilica, Roman mosaics and a wild island set on the horizon. As the ship sets sail, you think back to this northwestern Sardinia, hard-working and proud, which keeps its treasures on a human scale and gladly shows them to anyone who takes the time to go ashore.