The town of Buitrago del Lozoya is completely surrounded by an ancient wall originally built by the Moorish people. Within these walls lies the ruins of the Buitrago de Lozoya castle. The style of the castle is a unique mix of Mudéjar (moorish) and Gothic designs – tall, solid square towers combined with the typical pentagonal shaped often used by the ancient Arabs. It was built in the 15th century. It has a rectangular plan, with seven towers of various shapes (round, pentagonal, square), all in stone. The interior is in ruins.
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.