Cly is a castle in Saint-Denis, overlooking the Dora Baltea river, belongs to the so-called primitive style of castle, consisting of a keep with a surrounding wall. The ruins rise from a bed of metamorphic rock, on the edge of a fault line which extends to the Castle of Quart.
Cly was first mentioned in a document from 1207, in which the 'chapel sancti Mauricij de castro Cliuo' is mentioned among the goods of the Vicarage of Saint-Gilles in Verrès, but the keep has been dated to 1027 using an analysis of the tree rings in its timbers (dendrochronology). Originally a fief held from the Counts of Savoy, in 1376 the direct ownership passed to the Duchy of Savoy, which installed a castellanto administer it for them until abandoned in 1550. The castle fell to ruins in the centuries that followed.
Eventually the castle ruins became the property of the nearby town of Saint-Denis. The castle is visible atop the hill overlooking the town of Chambave. The castle is open to guided tours only in July and August.
References:The Château de Foix dominates the town of Foix. An important tourist site, it is known as a centre of the Cathars. Built on an older 7th-century fortification, the castle is known from 987. In 1002, it was mentioned in the will of Roger I, Count of Carcassonne, who bequeathed the fortress to his youngest child, Bernard. In effect, the family ruling over the region were installed here which allowed them to control access to the upper Ariège valley and to keep surveillance from this strategic point over the lower land, protected behind impregnable walls.
In 1034, the castle became capital of the County of Foix and played a decisive role in medieval military history. During the two following centuries, the castle was home to Counts with shining personalities who became the soul of the Occitan resistance during the crusade against the Albigensians.