Ganges is a commune in the Hérault department in Occitanie in southern France. Ganges is situated at the confluence of the Hérault and Rieut…Ganges is a commune in the Hérault department in Occitanie in southern France. Ganges is situated at the confluence of the Hérault and Rieutord rivers. The castle, of which only ruins remain, was the scene of a murder in the 17th century. The beautiful Dianne de Roussan was killed by her husband's brothers, who wanted her large fortune. They were caught and subsequently executed.