The Génissiat Dam is a hydroelectric dam on the Rhône in France near the village of Injoux-Génissiat.
Construction began in 1937, but was delayed by World War II, and the dam did not start generating power until 1948.
By 1949 it had the greatest capacity of any dam in Europe.
Wikipedia https://en.wikipedia.org/wiki/Génissiat_Dam
Address Route du Barrage, 74910, France
Coordinates 46°3'8.344" N 5°48'45.553" E