Châtel de Theys, Medieval castle in Theys, France

Châtel de Theys consists of two stone buildings on a rocky spur. The older, built 1279–1283, faces north over the Grésivaudan valley and holds a first-floor hall about 6 m high and 60 m², entered from outside at 5 m via a wooden structure. Its walls and ceiling keep 150 m² of early 14th-century painting. The second building, from about 1325, wraps the southwest corner and has windows with trefoil frames and carved bases.

The Aynard family, lords of Domène and La Pierre, held Theys until 1246, when the Aynard brothers exchanged it with Guigues VII, Dauphin of Viennois, for Savel. The present Châtel was raised between 1279 and 1283 by the local Bellecombe family on a motte with a bailey; dendrochronology dates its ceiling. A second building followed from about 1325. The Aynard castle on the motte lay in ruins by the early 15th century.

The wall paintings depict scenes from Arthurian legend that were popular during the castle's construction period. They reveal the intellectual world and reading habits of medieval nobility.

The site is currently undergoing restoration work and remains closed to the public. Visitors interested in medieval architecture can inquire locally about renovation progress and future access opportunities.

The painted decoration was reported in 1853 by a reader's letter to the Vœu national, but its subject stayed unidentified until Philippe Walter, a medieval French literature professor at Grenoble, recognised figures from Chrétien de Troyes's Conte du Graal after seeing two quatrefoil medallions in 1991.