Hald Castle was built in 1528 by the bishop Jørgen Friis, who was the last Roman Catholic bishop of Viborg. It is said that Friis was one of the first prisons in Hald tower after the Reformation. The castle was left to decay and in the 1700s it was abandoned. Anyway in late 1800s the owned Christopher Krabbe reconstructed the tower which is today the most visible part of the former castle. Today castle ruins are open to the public for free.
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.