The Castle of Charles V is located in the strategic area of Hondarribia, at its highest point. It still conserves the structure of a medieval fortress and its defensive appearance. It was built in the 10th century by King Sancho Abarca of Navarre, although it was subsequently reformed by Emperor Charles V. The building served as both a castle and a palace, both connected by an interior courtyard. The castle had a square floor plan with sturdy walls. Highlights of the main facade include the doorway, rather small in size and decorated with an arch framed by the characteristic Islamic moulding known as an alfiz, over which can be seen the imperial coat of arms with the two-headed eagle of Charles V. It has today been restored and converted into a Parador hotel.
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.