The Marino Mithraeum was constructed on top of a pre-existing cistern that was excavated in tuff rock, and was rediscovered by luck in the 1960s.
In 1963, while extending a cellar on Via Borgo della Stazione, the Mithraeum of Marino was discovered by chance. The Mithraic cult, which was dedicated to the god Mithras, was spread throughout Europe and the Roman empire by merchants and soldiers in the 1st century BC. The unique aspect of this cult was that the God did not accept sacrifices from his followers; instead, he himself sacrificed a white bull to ensure their safety and the fertility of the land.
The Marino Mithraeum was constructed on top of a pre-existing cistern that was excavated in tuff rock. It had a 29-meter long and 3-meter wide entrance tunnel. The back wall of the temple features a depiction of the tauroctony, where Mithras is shown wearing oriental clothing, including a star-studded cloak, a Phrygian cap, and trousers. He is seen slitting the throat of a white bull, with a dog and snake drinking the bull's blood at the bottom of the painting. The side walls depict significant episodes of the Mithras myth, including Mithras being born from a rock, riding a white bull, initiating the Sun into the mysteries, and letting water come out from a rock. On the left side of the painting, there are also representations of the Battle between Jupiter and Giants, and Saturn lying down. On the right, Mithras is shown dragging the bull into a cave by its back legs and shaking hands with two divinities, becoming allies.
This Mithraic painting is a rare and well-preserved artifact that dates back to the second half of the 2nd century AD. In front of the painting, there is a memorial stone with an inscription that refers to the slaves who worked in the peperino quarries and were followers of the sanctuary in ancient times.