The dogal Republic of Venice purchased the area of Butrint including Corfu from the Angevins in 1386; however, the Venetian merchants were principally interested in Corfu and Buthrotum once again declined. The Venetians began to invest in Butrint in the late 15th century, which seems a likely date for the Triangular Fortress construction. Musket ports opened at both ground level and along the parapet walk. Vaulted storerooms inside the fort carried artillery platforms above to train cannon on the approach to Butrint up the Vivari Channel. In 1798, however, the fortress was slighted by General Chabot, the commander of the garrison of the French dependency of Corfu.
Triangular Fortress takes the form of an irregular triangle with a tower at each point. Originally, it stood on an island in a pre-canalised river mouth, protected by an outer siege work or ravelin (a crescent-shaped defensive wall).The keystone of one the interior buildings bears a relief of the Lion of St. Mark, the symbol of the Republic of Venice.
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.