In the western part of Poetovio, in today’s Spodnja Hajdina, the oldest Mithras shrine in the Danubian provinces of the Roman empire was discovered. It was built in the mid-2nd century by employees of the Illyrian customs office based in Poetovio. The temple has been preserved in-situ. The shrine is lined by dedication stones with inscriptions and reliefs showing the myths and attributes associated with Mithras and the grades of initiation of its worshippers. A sculpture on one of the sacrificial altars in the central recessed part depicts Mithra’s birth from a rock. Special attention should be paid to a pillared altar with a sculpture of tauroctony, one of the only two such monuments still preserved.