Wilder and less developed for tourism than its cousin, the Lac de Ste Croix which is located a few leagues away, the Lac de Castillon is an artificial reservoir accumulating the turquoise blue water of the Verdon which gives it its particular colour.
This dam is the result of a long history.
In fact, as early as 1895, after a drought that ravaged crops throughout the south of France, the project for a dam appeared that would supply water to the orchards and fields of Provence. The irrigation of agricultural land was in fact the primary objective of this dam, whose construction finally began in 1928. The nationwide project will employ 1,200 workers, including many Germans hired as part of the repairs due by the Germany after the Great War. But the company managing the works went bankrupt in 1936 and the works did not resume seriously until the end of the 2nd World War with more than 2,000 workers (including again German prisoners of war) to end with the implementation service of the dam in 1948. The impoundment led to the disappearance of the village of Castillon, swallowed up by the waters of the lake which today bears its name. You can sometimes see some vestiges of the village, as well as an old bridge, when the level is at its lowest.
The lake of Castillon contains in its normal configuration 150 million m3 (8 km, 500 ha) of which 85 million are reserved for agriculture. But the dam is also a hydroelectric plant that manages to produce, on its own, the annual consumption of 31,100 people. And of course, tourism has developed a lot and is now an important activity around the lake.
In 2009, a sundial was inaugurated, the time lines of which are drawn on the vault of the dam. Covering an area of about 13,000 square meters, it is the largest sundial in the world. The time is given thanks to the curved shadow cast by the cornice overhanging the dam.