The Jajce Mithraeum is a temple dedicated to the Persian invisible sun god, Mithra. It was rediscovered in an archaeological dig in 1931. The temple dates to the early 4th century AD, although it could be as ancient as the 2nd century AD with repairs undertaken during the early 4th century AD. This particular Mithraeum is one of the best preserved sites in Europe.
Mithra was worshipped throughout the Roman era, from the late Republic to the later Imperial era. The cult of Mithraism spread from the Middle East to other parts of the Roman Empire throughout the Mediterranean basin, at first by military-political adventurers, travelers, slaves and merchants from the Orient. Later, Mithraism was spread by soldiers whose legions came into contact with the followers of the cult in the East.
The Jajce site is a typical spelaea. Mithraism followers typically sought to set up their places of worship in caves. In absence of such topographical features, they excavated the soil and built small single-celled temple (spelaea) to reinforce the impression of a cave.
The temple is now protected by a modern steel-and-girder cage with glass walls that allows visitors to see inside without entering. Visitors can enter with advance notice by contacting the Ethnological Museum of Jajce.
The Jajce Mithraeum is declared a National Monument of Bosnia and Herzegovina, and, including the old Jajce walled city core, the waterfall and other individual sites outside of the old city perimeter, as part of wider areal designated as The natural and architectural ensemble of Jajce, proposed as a UNESCO World Heritage Site list.
References:The Church of St Donatus name refers to Donatus of Zadar, who began construction on this church in the 9th century and ended it on the northeastern part of the Roman forum. It is the largest Pre-Romanesque building in Croatia.
The beginning of the building of the church was placed to the second half of the 8th century, and it is supposed to have been completed in the 9th century. The Zadar bishop and diplomat Donat (8th and 9th centuries) is credited with the building of the church. He led the representations of the Dalmatian cities to Constantinople and Charles the Great, which is why this church bears slight resemblance to Charlemagne's court chapels, especially the one in Aachen, and also to the Basilica of San Vitale in Ravenna. It belongs to the Pre-Romanesque architectural period.
The circular church, formerly domed, is 27 m high and is characterised by simplicity and technical primitivism.