Only the 7th century pilgrim itineraries mention it as containing saints Pamphilus, Candidus and Quirinus, alongside several other martyrs.
One itinerary, De locis sanctis martyrum quae sunt foris civitatis Romae, mentions Candidus and Quirinus, but no trace of their graves has been found.
The lowest and earliest floor dates to the 3rd century and lies 20 metres below the present ground level - it is made up of a 60-metre-long main artery, like the decumanus of an ancient Roman town, with galleries opening off it at right-angles.
As the catacombs were abandoned little by little, that of San Panfilo was completely forgottren until being rediscovered by Antonio Bosio, who penetrated its first level on 16 May 1594.
In 1920 and following years Enrico Josi rediscovered the catacomb a second time and definitively identified it: The first indication of the existence of a funerary centre, which led to the discovery of the necropolis on 25 February 1920, was a cable drilling in a construction site of the Società Anonima per Imprese Edilizie which cut into a group of tunnels partly strengthened by ancient tufelli and brick walls.