The Château de Calmont d'Olt is perched atop a basalt dyke. It provides a panoramic view of the Aubrac highlands.
Flint fragments and a polished stone axe are evidence of occupation of the site for 5,000 years. The ministerium Calvomantese was first mentioned in 883, in documents from the Abbey at Conques. It has always had a military significance, commanding the road from Rodez to Aubrac and, more widely, the crossing of the River Lot on the Toulouse-Lyon route. The building of the castle was begun in the 11th century built and continued until the Hundred Years' War with the building of a second curtain with eight towers in 1400. Beyond this date, there was no further development. Abandoned by its owners in the 16th century, the castle fell to ruin. The castle, in its present state, is an important milestone in the history of castle building in medieval Rouergue. It bears witness to the architectural adaptations of castles to the technical progress of the Hundred Years' War.
The castle is part of the Route des Seigneurs du Rouergue (Route of the Lords of Rouergue) which groups 23 castles.
The site highlights the theme of siege warfare. Full-scale war machines have been reconstructed and visitors may assist in the launching of projectiles with. There is a siege tower from the 15th century with bombards, trébuchets from the 14th century and pierrière from the siege of Toulouse from the 13th century. Visitors are also invited to take part in other demonstrations including archery, fencing and making chain mail.
References:The Château du Haut-Koenigsbourg is situated in a strategic area on a rocky spur overlooking the Upper Rhine Plain, it was used by successive powers from the Middle Ages until the Thirty Years' War when it was abandoned. From 1900 to 1908 it was rebuilt at the behest of the German kaiser Wilhelm II. Today it is a major tourist site, attracting more than 500,000 visitors a year.
The first records of a castle built by the Hohenstaufens date back to 1147. The fortress changed its name to Koenigsburg (royal castle) around 1157. The castle was handed over to the Tiersteins by the Habsburgs following its destruction in 1462. They rebuilt and enlarged it, installing a defensive system designed to withstand artillery fire.
The fortification work accomplished over the 15th century did not suffice to keep the Swedish artillery at bay during the Thirty Years War, and the defences were overrun.