The cult of Mithras was brought to Mainz by Roman legionaries as early as the 2nd century. It was in direct competition with the emerging Christianity, as both religions showed some parallels. The underground sanctuaries, called Mithraea, consisted of elongated vaults with a Mithras altar at the end and were painted to resemble the starry sky. The followers of the cult therefore met underground, but symbolically 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 Clerk of the Legion Prefect of the XXII Legion, ... has had this stone set after a vow.” A second altar made of Flonheim sandstone is heavily damaged, but also indicates, albeit barely legibly, the Mithras cult.
Both altars are now located in a covered passage at the Ballplatz and are accessible at any time.
