To be privately owned
Château de l'Arthaudière

In the French commune of Saint-Bonnet-de-Chavagne stands the Château de l'Arthaudière, a former fortified castle later transformed into a château. It was once the ancestral seat of the Arthaud and La Porte families and is now a protected historical monument.
History+
The origins of the Château de l'Arthaudière date back to the 13th century, when the oldest part, the round tower, was built. In the 15th century, an oblong keep was constructed, likely by the Arthaud family. Between the Italian Wars and the Wars of Religion, at the beginning of the Renaissance, the complex underwent alterations. A gallery with an upper floor was added to the western curtain wall and the tower. In the early 16th century, a chapel was founded at the base of the tower, mentioned by André I de la Porte in his will in 1517. In the 17th century, a spiral staircase was installed at the junction of the Renaissance portico with the northern buildings.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://en.wikipedia.org/wiki/File:Ch%C3%A2teau_de_l%27Arthaudi%C3%A8re_vue_g%C3%A9n%C3%A9rale.jpg
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: 45.1194, 5.2331