Antique Poetovio used to rank among the biggest centres of Mithraic religion in the Roman Empire. The western area, nowadays known under the name of Spodnja Hajdina, concealed the oldest Mithras Shrine in the Roman Upper-Danube Provinces, which was unearthed in 1898 and 1899. In the middle of the 2nd century AD, it was founded by administrators of the Illyrian customs station based in Poetovio.
The Shrine is kept in situ – on the site where it was found. It contains several votive stones with inscriptions and reliefs showing myths and attributes related to Mithras, and various stages of worshippers’ spiritual progression. In the central lowered part, a sculpture on the sacrificial altar represents Mithras’ birth from a rock. Special attention should be paid to a pillared altar with a sculpture of Mithras known as Taurophorus (Mithras with a bull on his back), which represents one of the only two such monuments still to be found in the world.
The residential area called Zgornji Breg, a densly populated residential quarter of Poetovio, boasts the biggest Mithras Shrine discovered in 1913. It has been preserved under the protective building erected by the former Museum Society. The Shrine from the 3rd century is rich in sacrificial altars bearing dedications of legionnaires of the Thirteenth Gemina and the Fifth Macedonica Legions. The original equipment of the Shrine comprises a votive relief dedicated to sublime Nutrices, a bust of the goddess of fertility – Magna Mater, a relief altar brought here from a Mithras Shrine discovered in Modrič na Pohorju, and a relief plate depicting Saxan, the patron saint of stone masons, brought here from Šmartno na Pohorju.