The underground catacombs of San Gennaro in Naples

The catacombs of San Gennaro, tucked away under the Rione Sanità neighborhood in Naples, are an archaeological and religious site. These underground passageways, carved out of tuff, a porous stone, span two levels, San Gennaro Superiore and San Gennaro Inferiore, and date back to the 3rd-4th century. Originally, the site may have been a pre-Christian cemetery later ceded to the new sect. It became an important religious burial site only after the entombment of Bishop Agrippinus. The second level was the one expanded so as to encompass the other two adjacent cemeteries.

The site was consecrated to Gennaro (Januarius) in the fifth century on the occasion of the entombment of his remains, which were later removed to the Cathedral of Naples by Bishop John IV in the 9th century. As the burial areas grew around the remains of Gennaro so did underground places of worship for the growing Christian faith. Due to severe looting between the 13th and 18th century, many of the tombs were vandalized. Restoration was made possible only after the transfer of skeletal remains to another cemetery. The catacombs were reopened in 1969 by the Archbishop of Naples and modern excavations started in 1971.

Sources: Wikipedia, OpenStreetMap, Wikidata, Wikimedia Commons