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:
Frösöstenen is the northern-most raised runestone in the world and Jämtland's only runestone. It originally stood at the tip of ferry terminal on the sound between the island of Frösön and Östersund. The stone dates to between 1030 and 1050. It has now been relocated to the lawn in front of the local county seat due to the construction of a new bridge, between 1969 and 1971, on the original site.
Frösö runestone inscription means: Austmaðr, Guðfastr's son, had this stone raised and this bridge built and Christianized Jämtland. Ásbjörn built the bridge. Trjónn and Steinn carved these runes.