The Château de Rosanbo, overlooks the Bô river valley. The origin of its name stems from this fact, as in Breton it means 'rock on the Bô'. The château, which was in the past the stronghold of the Coskaër de Rosanbo family, then later of the Le Peletier de Rosanbo family, is square in shape and has been developed and re-fashioned throughout its history. In the 14th century, a fortified castle was built on a strategic headland, located 4 miles from the bay of Saint-Michel-en-Grève in order to prevent the ascent of the Bô by invaders. In the 16th century, it was extended with a Gothic manor.
The buildings were further extended in the 18th Century by Louis Le Peletier de Keranroux, first president of the Paris parliament and husband of Geneviève de Coskaër (the last inheritor of that name). At the time of this redevelopment, the architect Joubert added a gallery to the château and a corner room overlooking the valley. The old kitchen was transformed into a wood pannelled dining room and, on the floor above, additional new space allowed small rooms such as private bathrooms and boudoirs to be created. At the end of the 19th Century, new suites were designed by the architect Lafargue, who was also responsible for the restoration of the châteaux of Josselin and Chenonceaux.
References:The Gravensteen is a castle in Ghent originating from the Middle Ages. The name means 'castle of the counts' in Dutch. Arnulf I (918–965), Count of Flanders, was the first to fortify this place, building a medieval bastion on this high sand dune, naturally protected by the river Leie and its marshy banks. This bastion consisted of a central wooden building and several surrounding buildings, also in wood.
In the early 11th century, the wooden building was replaced by a stone residence, consisting of three large halls that made up three storeys, connected by a stone stairwell. The monumental stone staircase, the light openings, the fireplaces built into the walls and the latrines were signs of considerable luxury and comfort in those days. There was probably also a tower.