The remains of the Castle can be visited
Château de Calmont d'Olt

The Château de Calmont d'Olt is a castle ruin in France, located in the Occitanie region in the Aveyron department, near the commune of Espalion. It stands on a basalt rock and offers a view over the Lot Valley.
History+
The site's history dates back over 5000 years, evidenced by finds such as flint fragments and a polished stone axe. The area was first mentioned in documents from the Abbey of Conques around 883. The castle's military significance was always high, as it controlled an important road from Rodez to Aubrac and a ford of the Lot River on the Toulouse-Lyon route.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: Jean Thiers
This description draws on the facts documented in the linked Wikipedia article; Wikipedia content is licensed under CC BY-SA 4.0. Wording and editing: Mobile History.
Location: 44.5179, 2.7526