1.30 meters long and 1.15 meters high, it is the only bas-relief directly sculpted in the rock that can be seen in France. In the 3rd century, this bas-relief was indeed the back of a temple, Mithraeum, which went all the way to the riverside. The bas-relief was to be demolished in 1880, when the railroad was built, but Priest Paradis was strongly opposed to this decision. He managed to have it preserved and protected.

The worship of Mithra is of Indo-Iranian origins and was brought here by the Romans for their fight against Gallic gods and beliefs, druids and Christians. On the bas-relief, the god is represented by a young man riding the bull he is sacrificing. The ears of wheat gushing out of under its tail symbolize the new life brought by the animal’s death. In front, one can see a cartouche with Latin inscriptions. Among the several translations which were made to French, the most commonly accepted is: “A la divinité de Mithra, au Soleil très grand, Titus Furius Sabinus a fait faire et dédier cette image du dieu invincible à ses frais”.