In the right-hand aisle of Genoa cathedral, resting on a plinth with almost no explanation around it, there is a bomb. It is a 381 millimetre naval shell, more than a metre tall, and the story it carries is the best way to start telling you about this church.
It was fired by the British battleship Malaya on the morning of 9 February 1941, during the naval bombardment of Genoa. The shell hit the cathedral, went through the roof and two walls, bounced around inside and came to rest without exploding. It was defused over the following days. What you see today is a full-size replica, and it is worth knowing: the original device is no longer there.
Watch the opening hours of the Treasury Museum, which is the most interesting part of the complex and keeps a calendar of its own: it opens Monday to Saturday, mornings and late afternoons only, and closes on Sunday. Going to San Lorenzo on a Sunday means seeing the church and nothing more.
The black and white stripes are not decoration
Why do so many churches in Liguria and Tuscany have a striped façade? In Genoa the answer is not aesthetic but legal. The alternation of white Carrara marble and black promontory stone, a dark limestone quarried a few kilometres from the city, was a privilege the Republic granted only to families who had rendered a recognised service to the state.
Anyone who had not obtained it could not use that combination on their own palace, and anyone who had displayed it over the doorway at home like a title. The cathedral takes it across the whole façade, along the flanks and up the bell tower, because it is the church of the entire city.
The façade, raised between 1230 and 1312, is Gothic imported from France, with three splayed portals and a loggia. The two marble lions at the sides of the steps are nineteenth century, added in 1840, and the Genoese have been sitting on them for almost two hundred years.
The bell tower that was never finished and the tower that stayed
Look at the two sides of the façade: they are different. On the right stands the bell tower, completed in the sixteenth century with a pyramidal spire; on the left there is a squat stump that stops at the height of the loggia. It was the second tower, planned in the design and never carried through for lack of money.
It is the kind of detail that makes a building site three centuries long readable. The cathedral itself mixes Romanesque stone in the lower part of the flanks, French Gothic on the façade, a Renaissance lantern tower by Galeazzo Alessi above the transept and Baroque chapels inside.
The chapel of St John the Baptist, which is why the treasury exists
The left aisle opens onto a Renaissance chapel entirely faced with marble, built between 1450 and 1496 to hold the relics of the Baptist, which the Genoese said had been brought to the city from Myra in 1098, on the way home from the First Crusade.
The chapel had a rule that held for centuries: women could not enter. The ban went back to the belief that a woman, Salome, had caused the saint’s death, and it was lifted only in the twentieth century. The silver processional ark that held the relics came out once a year, on 24 June, carried on shoulders down to the port for the blessing of the sea.
The Baptist is the patron saint of Genoa, and the whole treasury of the cathedral turns around his cult. It is the right way into the museum below.
The Treasury Museum: the container is worth as much as the contents
Under the presbytery, in a space dug out of the rock that you reach through a side door, lies one of the finest museums in Italy, and almost nobody talks about it. Franco Albini designed it between 1952 and 1956, and it has been studied in schools of architecture ever since.
Albini did not build rooms: he built four circular chambers in exposed promontory stone, roofed with corbelled false domes, dark, linked by a narrow corridor. The objects sit on slender supports that seem to touch nothing, each lit on its own in the darkness. The effect is that of a tholos tomb, and the quotation is deliberate: you go down into an underground place to see things that stayed hidden for a long time.
If Italian twentieth-century museography interests you, this is one of the three or four places to see, along with Carlo Scarpa’s Castelvecchio. It is also why the museum earns the visit of anyone whom relics leave indifferent.
The Sacro Catino, which is glass and not emerald
How do you take apart a legend that lasted seven hundred years? In Genoa a transport accident did the job, and the conclusion is more interesting than the beginning. The Sacro Catino, the sacred basin, is a green hexagonal dish about forty centimetres across, which the Genoese brought home from the capture of Caesarea in 1101. For centuries it was believed to be a single enormous emerald, and in the thirteenth century the identification with the Holy Grail, the cup of the Last Supper, began to circulate.
The basin was so precious that the Republic regulated its display by law, forbidding anyone to touch it with metal objects. In 1806 Napoleon had it carried to Paris as loot; it came back in 1816 and broke on the return journey. It was the break that revealed it was not emerald but glass, probably an Islamic piece of the medieval period, perhaps of the ninth or tenth century.
The remarkable thing is not that the legend was false. It is that the basin remains a piece of ancient glass of extraordinary quality, and that its story says more about the Genoa of the crusades than a real emerald would.
The platter of the Baptist and the ark of Barbarossa
Next to the basin stand the other two major pieces. The chalcedony platter, a translucent slab worked in Egypt or Palestine in the first century, which tradition identifies as the dish on which the head of the Baptist was laid; the gold and enamel decoration with the head of the saint was added by goldsmiths from Limoges in the fifteenth century, that is one thousand four hundred years later.
And the casket known as the ark of Barbarossa, a twelfth-century reliquary in gilded copper which tradition says the emperor Frederick Barbarossa gave to the city. Here too the attribution is more legend than document, but the object is genuine and precious.
Practical information
Checked on 3 September 2026 on the official Musei di Genova site and on the Treasury Museum page of the Diocese. Prices and hours change: check again before you travel.
Tickets. The cathedral is free to enter. The Treasury Museum costs 6 euros full price and 5 euros reduced, and the reduction goes to groups of more than ten people, to visitors over 65 and to the police and the armed forces.
Opening hours. The cathedral opens every day on liturgical hours and closes during services. The Treasury Museum opens Monday to Saturday from 9 am to noon and from 3 pm to 6 pm, and it stays closed on Sunday.
Getting there. The cathedral stands in piazza San Lorenzo, in the heart of the old town. From the San Giorgio metro stop you walk there in five minutes. From via Garibaldi you come down through the alleys in a quarter of an hour.
How long it takes. The cathedral on its own wants forty minutes. With the Treasury Museum you reach an hour and a half.
Where to go next
The cathedral is the second stop of the first day of the full itinerary, which you will find in What to see in Genoa in 2 days. If the black and white stripes have caught your interest, the system of privileges that governed them is the same one that regulated the houses of the patricians: The Rolli palaces tells that story.
Photographs by Zairon, Palickap, Bbruno and Sylvain Billet from Wikimedia Commons, CC BY-SA licences.
