Château Gaillard is a medieval castle ruin overlooking the River Seine above the commune of Les Andelys, in the French department of Eure, in Normandy. It is located some north-west of Paris and from Rouen. Construction began in 1196 under the auspices of Richard the Lionheart, who was simultaneously King of England and feudal Duke of Normandy. The castle was expensive to build, but the majority of the work was done in an unusually short period of time. It took just two years and, at the same time, the town of Petit Andely was constructed. Château Gaillard has a complex and advanced design, and uses early principles of concentric fortification; it was also one of the earliest European castles to use machicolations. The castle consists of three enclosures separated by dry moats, with a keep in the inner enclosure.