Castillo de Moguer was renovated and enlarged in the 14th century. The oldest record document of castle dates from 1362, but it probably existed already in the Moorish age.
The castle was built of mud-based mortar gravel, clay and lime. It is of an imperfect square plan 44 by 45 metres in size, with four towers at the corners. A moat surrounded the castle, as evidenced by written records, but is not currently visible. Access to the castle was across the northwest side, now Santo Domingo Street, via a ramp. Each tower measures 9 by 9 metres and contains two chambers with a covered brick dome. The four towers were topped by battlements. A cellar dating to the 18th century, measures 22 by 10.5 metres and serves as the headquarters of the Tourist Office.
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.