From ancient tomb to Christian site
The earliest nucleus of the complex dates to the 2nd century AD, when a noble family tomb started the story beneath today's Via Capodimonte. In the 4th century AD, the area expanded after the deposition of St. Agrippinus, and the underground basilica tied the place to Christian devotion. You feel that shift immediately: the catacombs read less like a corridor of graves and more like a buried city of ritual.
The 5th-century San Gennaro turning point
Between 413 and 431 AD, Bishop John I brought the remains of San Gennaro here, and the catacombs became a pilgrimage destination and a coveted burial place. That is the moment the site stops being only archaeological and becomes emotionally Neapolitan. The route makes far more sense once you read it as a place of devotion, not just a museum underground.
What stands out on the visit route
Look for the bishops' crypt, the broad underground basilica spaces, and the frescoes that still hold human presence on the walls. The upper catacomb preserves some of the earliest Christian paintings in southern Italy, while later paintings and mosaics show how the site kept changing instead of freezing in one era. If you slow down for the art, the visit feels richer than a simple walk-through.
When the relics left and the memory stayed
In 831 AD, Lombard prince Sico I took the remains of San Gennaro to Benevento, and they later spent time at Montevergine before returning to Naples Cathedral. Yet the catacombs never lost their symbolic weight inside the city. That long detour explains why the place still feels larger than the relics physically housed there today.