Frankenberg Castle was constructed during the 13th century and historically it was the seat of a Vogt, local administrator. Until the end of the 19th century, the castle consisted of a broad forecastle, a farmyard, and a main castle (which was completely surrounded by water).
With the introduction of the French Constitution of 1793, Frankenberg Castle lost its status as a fief of Jülich. Between 1834 and 1838, the property underwent comprehensive renovation and modernization.
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.