Rocher de l'Horloge (Clock Rock) is located on the cliff of Voidon above Chassezac River near the village of La Gare-Grospierres in Ardèche department of France. This small but attractive arch has a measured span of 1.3 meters. From the opposite bank of Chassezac River, the rock look like as a small clock hence the name. Rocher de l'Horloge is named but not spoted on IGN topographic map Top 25 number 2839 west Les Vans.