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 Citadelle of Quebec is an active military installation and official residence of both the Canadian monarch and the Governor General of Canada. It is located atop Cap Diamant, adjoining the Plains of Abraham in Quebec City. The citadel is the oldest military building in Canada, and forms part of the fortifications of Quebec City, which is one of only two cities in North America still surrounded by fortifications, the other being Campeche, Mexico.
The first fortifications in Quebec were built by the Governor General of New France Louis de Buade, and completed just in time for the Battle of Quebec in 1690.
After the British conquest in the second half of the 18th century, the problem of Quebec City's defences grew more acute.