Hajdina and its surrounding area was one of the largest Roman provincial centres of Mithraism in Europe. Archaeologists discovered five Mithraea in this area. Romans left a rich legacy in this region, which includes temples dedicated to Mithras – Mithraea. These temples were used for religious ceremonies and represented a cave in which Mithras performed the first offering. The oldest Mithraeum in the Roman provinces along the Danube is the so-called First Mithraeum in Spodnja Hajdina, which is exhibited in situ.