This vast woodland (10 700ha/26 440 acres) is "one of the natural wonders of France and the crowning glory of the beech tree", where visitors feel belittled by tree trunks often in excess of 20m/66ft in height. Within its verdant boundaries, you can also admire the former abbey of Mortemer and two interesting castles, at Fleury-la-Forêt and Vascoeuil.