Not necessarily to buy tickets online. You can get them at the ticket office in the church (which is also the meeting point and not the altar). The experience was interesting and worth seeing when in Naples. You also get an entry to the second Catacombs di San Gennaro as part of this ticket, which can be used within a year I was told by the tour guide, although this is not confirmed.

excellent experience never done roman catacombs tour before was really good and intresting guild tells u about the history what happened there and the graves there.the only down side u cant do videos inside but other than that really happy with the tour and if go to naples again will do it again for sure.

I recommend trying this experience! It immerses you in the Sanità district and in the history of ancient Naples, with truly prepared, kind and helpful guides, who transmit passion! It is not specified, but by purchasing the ticket, a ticket is also given for free to visit the Catacombs of San Gennaro, always with a guide (and vice versa). Being two very different catacombs, I recommend seeing them both! These guys really deserve all the support they can get! Well done !!