Château de Châteaubourg, Medieval castle in Châteaubourg, France.

The Château de Châteaubourg stands on a rocky outcrop above the right bank of the Rhône. Its buildings include a round tower with a conical roof, a lower range with a flat roofline, and a taller square tower of mottled stone. An arched opening is set into the rock below the towers.

The fortress appears in 12th-century documents under Lord Rogier II of Clérieux, who hosted King Louis IX during the crusades. This royal connection made the site an important point in the regional medieval power structure.

The castle's name changed to Rochebourg during the Revolution to erase its feudal past. In the lower courtyard stood a place of worship. A drawbridge and a prison existed before the Revolution, mentioned in the lord's instructions to Mr. Dupaillé for various works.

The fortress now operates as a functioning hotel where visitors can stay and explore the premises. The location is clearly visible from the valley below and remains naturally accessible from the river side.

The lords of Châteaubourg, the Clérieux family, also held La Roche de Glun and Glun across the Rhône, and Rogier II was remembered for extorting money from travellers, pilgrims and sailors. Joinville records that Louis IX, sailing for the crusade, besieged La Roche de Glun, put Rogier and his people to the sword, then lodged at Châteaubourg. In 1821 the priest Lapassa wrote that the castle had cost its lord over 60,000 francs to build.