On the Grande Balise road, a few hundred meters from the forest path, you will discover the venerable nail oak on the right. This is a 500 year old tree believed to have healing powers against furunculosis in humans. This oak would be the only survivor of a group of sessile oaks felled before 1742, it is today isolated among younger subjects. With a circumference of 4.20 meters at 1 meter from the ground, it is distinguished by a niche attached to its trunk which houses a Virgin and Child, and above all by a trunk covered with hundreds of nails. Formerly, the word nail designated boils; and popular tradition attributes to this oak the power to cure these painful conditions. An ancient pagan rite was practiced: it involved coming alone, at night, out of sight, to rub coffin nails against the sick part of one's body; then go around the tree seven times, address a prayer to the soul of the tree, drive the nails into the trunk on the side that never sees the sun. The rite ended by walking backwards and saluting the tree. petitfute.com/v75850-vallons-de-l-erdre-44540/c1173-visites-points-d-interet/c974-site-naturel/533485-le-chene-aux-clous-du- patisseau.html