Not far from the airport at Špilnik, around 2 kilometers from the road towards Gospić, there is a shrine from 2nd and 3rd century AD where the followers of the god Mithras made offerings and performed cult pagan ceremonies.
The Gacka region is the second Croatian destination according to the number of Mithras’ shrines, right after Salona near Split. Besides this shrine, a second one can be found in Rajanovgrič in Čović, a third one on the slope of Godača in Sinac, while one relief plaque ended up in the Archaeological Museum in Zagreb, at one time having been found in the stone fence of the vicarage in Sinac. Apart from the abovementioned, several more stone inscriptions have been found mentioning the pagan god Mithras because, according to the belief, Mithras was born from stone.
In the Late antiquity, Mithraism was also popular in the Gacka region, brought by Roman slaves, traders, and craftsmen. The Mithras shrine in Kraljevstolac was carved into stone, while the relief depicts the most important event of the Mithras cult – tauroctony, i.e., the moment when Mithras slays a bull. Mithras is depicted as a young man in a Phrygian garment, kneeling on the bull, holding it by its nostrils, while slaying it with the other hand. Rituals were performed in front of the Mithras’ shrine, but not much is known about them today because they were a tightly guarded secret.
This religion was reserved only for men and the cult members were connected as brothers.
The followers of the cult went through seven degrees of initiation and they ate bread with wine to commemorate the Mithras and Sol Invictus banquet after sacrificing the bull.