Genoa's cathedral is dedicated to St. Lawrence – or San Lorenzo in Italian – and there are a few names you might see that all mean this same church. The Genoa Cathedral, St. Lawrence Cathedral, the Genoa Duomo, or the Cattedrale di San Lorenzo – all of those refer to the same place.
Originally founded in the 5th or 6th century, the San Lorenzo Cathedral was built in the early 12th century. It was partly rebuilt in the early 14th century – including the completion of the facade – and there are internal features that have been added since then. Those with a keen eye for architectural styles will no doubt notice the different time periods represented both inside and out.
Among the things to see inside the San Lorenzo Cathedral are some 14th century frescoes on walls and ceilings in some of the chapels, the chalice supposedly used by Christ during the Last Supper (held in the Treasury Museum beneath the cathedral), and a shell that didn't explode when it hit the cathedral during World War II.
The San Lorenzo Cathedral is open Monday-Saturday from 9am until noon and then again from 3pm-6pm, and it's free to enter. The Treasury Museum, located in a crypt underneath the cathedral and accessed from the San Giovanni Chapel on the left side of the church's interior, is open the same times as the cathedral but you can only get in with a guided tour. The Treasury has a €5.50 entry fee.