La Crau steppe. Stones deposited on a wide alluvial plain in southern France known as La Crau. This area is the former delta of the River Durance, which deposited these stones here. This stony steppe has a unique flora and fauna, including several species of ground-foraging birds and low-lying steppe vegetation. Like the Camargue to the west, this area is of great importance and protected for its biodiversity. La Crau covers an area of around 500 square kilometres.