Dagstuhl Castle ruins overlooks the newer Schloss Dagstuhl in the valley below, which is historic but has been converted for use as a conference centre. The castle was founded by Knight Boemund of Saarbrücken sometime before 1290, probably for Bohemond I von Warnesberg, Archbishop of Trier. The name derives from the German word for roof, 'Dach', because of the roof-like shape of the hill on which the castle stands.The castle ruins have been archaeologically explored and were improved for public access in 2004.
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.