Located in the Kaylaka Park a few kilometers away from Pleven, Storgosia is ancient fortress dating back to the Roman era and containing the ruins of towers, gates, residential houses, a public storehouse and a large church believed to be constructed around the 4th century. Originally built as a road stop, it became a fortress to protect itself from raids and attacks.
The fortress existed until the end of the 6th century, when the settlement of the Slavs apparently led to its abandonment and during the rule of the Ottoman Empire the fortress was practically destroyed (probably in the 16th century), so that the stones could be used for the construction of a wall around the Turkish barracks in Pleven.
Archaeological excavations have been carried out on the site and a few basic structures of buildings can be seen.
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.