La Roche-Guyon is a commune in the Val-d'Oise department in Île-de-France in northern France. It is located in the Vexin regional nature park.
The commune grew around the Château de La Roche-Guyon, upon which historically it depended for its existence. The commune's population in 2019 was 479.
Wikipedia https://en.wikipedia.org/wiki/La_Roche-Guyon
Coordinates 49°4'51.857" N 1°37'50.076" E
