The cult of Mithras was brought to Mainz by Roman legionaries in the 2nd century AD: it competed strongly with the rising Christianity, as both religions shared some similarities. The cultic meeting places, the so-called Mithraea, were situated underground and consisted of elongated vaults with a Mithras altar at one end. The vault was painted as a starry sky. The followers of the cult therefore only seemed to descend underground; they actually gathered under the canopy of heaven.
The well-preserved altar is made of Odenwald marble. Its originally red inscription reads: "To the unconquered sun god Mithras and Mars, Secundinius Amantius, chief of the chancellery of the legion prefect of the XXII Legion, ... has set this stone according to a vow." The second altar made of Flonheim sandstone is heavily damaged. However, its - very weathered - inscription also associates it with the Mithras cult.
The remains of the two dedication altars are located in a covered passage on the town square and can be viewed at any time.
