One of the largest natural springs in the world Fontaine-de-Vaucluse is in the homonymous city of Provence, once very beloved by the Italian poet Petarque. The source is a picturesque "lake" that gives way to the surface of a powerful underground river that collects streams from an area of ​​about 1100 square kilometers from the Vaucluse mountains to the south and to the Ventoux and Lure mountains in the north .

The average discharge velocity of underground streams gaining freedom here is 22 cubic meters per second, that is, about 22 thousand liters or 22 tons per second! The spectacle, truly, bewitching with its beauty and power. Fontaine de Vaucluse is one of the deepest karst caves in the world (308 meters).