Mithreum (3./4. century A.D.) is the oldest national monument in Jajce. The cult of the invincible god of the sun- Mithra was widespread throughout the all prov- inces of the Roman Empire including the province of Dalmatia to whose borders belonged to the biggest part of today’s  Bosnia and Herzegovina.

The followers of the Mithraism strived to locate their places of worship in caves, but they also built small single-celled temples or spelaea; where the terrain permitted, they embed- ded them into the ground. Such example of the temple-spelaea carved in a rock is located in Jajce in the eponymous street, and represents a unique and rare example. Relief is showing god Mithras wearing a Persian garments, with a fluttering cloak, and with one knee he is crushing a bull, while seizing him by the muzzle with his left hand and stabbing him in the heart with his right. He is being assisted by a dog, a serpent and a scorpion.

Relief of Mithras is the only example in Bosnia and Herzegovina, which by the appearance of torchbearer has also two free Mithraic sculptures. This ancient monument was accidentally discovered during a private building construction in the beginning of  20th Century. New protective structure of glass around the Temple, bulit in 2012, makes this monument accessible for all visitors without mandatory entry into it. If the visitors want to enter the building, it is nec- essary to call the number (0) 30 658 268 or contact directly into the Ethno Museum of Jajce (The building of the Old elementary school near the Catacombs).