Conrad I, Count of Vintimiglia, built the castle in Roquebrune-Cap-Martin in 970 to defend the Western border of his feudal domain from attack by hordes of Saracens that rampaged around the area. Initially the entire village was encompassed by the castle. The keep's military strength was reinforced in the 15th century by the Grimaldi family. In 1808 the castle was sold as a Bien National to five Roquebrune inhabitants. A century later, in 1911, it was sold again – this time to wealthy Englishman Sir William Ingram, who set about renovating it but eventually gave it to the town of Roquebrune in 1921. The castle overlooks the medieval village and its atmospheric alleyways, sometimes carved out of the rock itself.
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.