set of cataracts in the Pyrenees range near the head of the Pau Stream in southern France. At 1,450 feet (442 m), it is among the world's highest waterfalls. Fed by water from Lake Glacé in Spain and by melting snow, its two main falls merge into one in spring and early summer, when the water volume is greatest. The Grande Cascade is in the Pyrénées Occidentales National Park.