Alburquerque was conquered from Moors by Ferdinand II of León in 1166. It changed hands couple of times before was finally in the hands of Christians in 1217. The castle was built in the late 13th century.
In the mid-15th century Álvaro de Luna, Master of the Order of St. James, built the famous keep. But that is not the only identifying mark on this castle as it has several palace-style out buildings, some outer defence resources in the barbican and a curious pentagonal tower, crowned battlements with sharp points ending in balls. Furthermore, the fortress is protected by three levels of walls scattered with small towers and several doors.
In the early 18th century the city was in the hands of Portuguese and several Vauban-style bastions were added to the complex.
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.