About the town » La Roche-Guyon, Val d'Oise, Île-de-France, France

La Roche-Guyon is a commune in the Val-d'Oise department in Île-de-France in northern France. The commune grew around the Château de La Roche-Guyon, upon which historically it depended for its existence. The commune's population in 1999 was 550.