Château de la Roche du Roi, Historic monument on hillside in Aix-les-Bains, France.

Château de la Roche du Roi is a castle on a hillside above Aix-les-Bains, featuring a rectangular shape with round towers topped by domes and a central polygonal keep. The structure sits above two basement levels that rise above a raised ground floor.

Construction began in 1897 and finished in 1900, directed by the town architect Jules Pin (aîné) with the firm Léon Grosse, at a cost of 496,000 francs. The building was listed on the supplementary inventory of monuments historiques in 1983, then classified on 23 April 1986. After a long legal battle, the town of Aix-les-Bains bought it in 2015 for 485,000 euros, and restoration work started in 2016.

The castle blends Oriental palace elements with Renaissance design, and its entrance features Art Nouveau wrought iron gates. This mixing of styles shapes how the building looks and stands out in the landscape.

The castle sits on a hillside with views stretching over southern Aix-les-Bains and toward Tresserve hill. You can reach it via Boulevard de la Roche-du-Roi, and the elevated position makes it easy to orient yourself when visiting.

In 1982 a foreign buyer offered to buy the castle and rebuild it stone by stone in his own country; the owner at the time, Gilbert Duranton, confirmed the offer to the local press. In 2005 a Second World War MK2 grenade was found in the basement.