The Angevin-Aragonese castle in Agropoli has a triangular shape with three circular towers and stands on the highest point of the headland. Around the walls there is a wide and deep moat which today is visible just on the side of the village and disappears while on the eastern side because of agricultural works and past landslide.
The castle was built on the 6th century Byzantine foundations by the Aragonese reign in the 15th century. The Inside part of the castle is composed of a central square, nowdays used as on open air theater, and on the northern side by the “French Room”.
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.