Château Gaillard is a ruined medieval castle in Normandy, France.
It was built built in limestone c. 1196–1198 by the master military strategist Richard I (Richard Coeur de lion, the Lionheart). Some historians think that he designed it himself. It was an early Concentric castle and one of the first to feature machicolations, and flanking towers. The castle consists of three enclosures separated by dry moats, with a keep in the inner enclosure.
It was lost to the French by the incompetent King John and played a major part in the Hundred Years' War, exchanging hands several times. It was slighted in 1599–1611, and is now in ruins. The château Gaillard can be visited throughout the year. The keep is open in summer paying. Guided Tours in English, French and German from mid March to Mid November. Parking available.