The Régalon canyon

Below, the Régalon notches the south side of the Petit Luberon with a sumptuous and surprising gash! How did this little stream create this incision in hard limestones? The cause of this is in the closure of the Strait of Gibraltar, 6 million years ago. The Mediterranean Sea is lowered to 1,500m. The entire river network will sink and dig canyons. This is the case for the Rhone river which used to flow 900m lower down from the Durance and the small river of Régalon.