The Angevine-Aragonese castle of Gallipoli dates back to the 13th-14th centuries, but the town used to have a stronghold already during Roman time, together with towers enlarged by the Byzantines and by the Normans. The Angevins and the Aragonese modified the structure of the fortress, but Francesco di Giorgio Martini was the one who made important changes. During the 19th century the moat was filled up and the arches which used to support the lift bridge were filled in.
The fortress has a square base strengthened by the four towers. The tower Vedetta, topped by merlons, has a polygonal shape. The other towers are surrounded by a string course and are decorated with small arches. The eastern curtain, the Rivellino, is a fifth circular tower separated from the rest of the walls and has not been renovated yet. Inside it, there are large rooms with barrel and cross vaults.
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.