Pilgrims or visitors roaming the catacombs’ galleries and ever-winding paths, who stop to admire the frescoed and decorated cubicles or tombs, feel the attraction of suggestive representations of biblical or common life scenes. But even more so, they are inevitably drawn by a true world of symbols, whether painted, as graffiti, or engraved on stone.

The meaning of some of them is known, while others appear more mysterious and difficult to fathom; regardless, all refer to a very essential language, used by the first Christian generations to assert their faith and distinguish, in a Christian manner, the graves of loved ones or of the first witnesses of the faith: the martyrs.