1. The Catacombs of San Gennaro are ancient underground burial sites located in Naples, Italy. They date back to the second century AD and were used for Christian burials until the ninth century. The catacombs contain various frescoes, mosaics, and sarcophagi that offer insight into the early Christian community in Naples. The site is named after Saint Gennaro, the patron saint of Naples, whose remains were originally buried in the catacombs. The catacombs were rediscovered in the seventeenth century and have been open to the public since then.

2. The Catacombs of San Gennaro are open daily from 10:00 am to 5:00 pm. Their phone number is +39 081 7443712.

3. Admission to the Catacombs of San Gennaro costs €10 for adults and €5 for children, students, and seniors. The site can be reached by taking the Metro Line 2 to the Materdei station and then walking 10 minutes to the catacombs. Alternatively, buses 168 and C63 stop directly outside the catacombs.