Achalm is a ruined castle located above the towns of Reutlingen and Pfullingen. Situated on the top of a hill at the edge of the Swabian Alb the ruins of the 11th century castle are topped by a look-out tower from 1838.
Achalm Castle was built around 1030 by Gaugraf Egino and Rudolf of Achalm. The name Achalm appears to refer to a nearby stream, the Ach which comes from the River Alm. The castle was expanded in the 11th Century with a second tower. However the von Achalm family died out shortly thereafter. The castle passed through several owners including the House of Welf. In 1234 the son of the Holy Roman Emperor Frederick II, King Henry VII, rebelled against his father, the Emperor. The owner of Castle Achalm, Heinrich of Neuffen, sided with the rebellious King Henry VII. Following the Emperor's victory over his son Henry VII, Castle Achalm became the personal property of the Emperor's family, the House of Hohenstaufen. Castle Achalm remained a Hohenstaufen property for a time. The castle then passed into the control of the House of Württemberg. In 1377 Graf or Count Ulrich of Württemberg marched from the castle to attack the town of Reutlingen. While he besieged the city, troops from the Swabian Cities League marched to defend the city. Ulrich's troops were defeated and Reutlingen remained a Free Imperial City.
Over the following centuries, the castle began to lose its military value and began to collapse. During the later years of the Thirty Years' War, in 1650, the castle was partially destroyed to prevent enemy forces from using the castle for shelter. Later the stones were removed to build houses in the village. In 1822 the future king and emperor William I had a stone look-out tower built on the foundation of the old tower. The tower was repaired and renovated in 1932 to prevent it from collapsing.
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.