Ernstbrunn castle became the seat of the Ernstbrunn branch of the Counts of Sinzendorf in 1592. After the last Sinzendorf died in 1822, it was inherited by the Köstritz branch of the ruling princely House of Reuss of whom it remains their main family seat until today.
The castle is an elongated structure with four ascending courtyards on the northern slope of the Semmelberg above Dörfles. The medieval core castle on the northern rocky spur was continuously expanded during the Late Renaissance, Baroque, and Classicism periods with new groups of buildings. The core castle, dating from the 12th and 13th centuries and surrounding the innermost courtyard, sits on a free-standing limestone rock on three sides, which drops steeply towards the village of Dörfles. It forms an elongated octagon. The wall thickness of the outer wall is up to three meters. It is further reinforced on the southeast by the square keep. Originally, this keep had only three floors but was extended by an additional floor in the 16th/17th century.
In front of the gate is an early Baroque fountain. This fountain has a total of 16 coat of arms representations, 4 at the top of the shaft below the fountain bowl and 12 in pairs around the edge of the hexagonal basin.
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.