These are very old flints, protected in the Natagora site. No fewer than 13 cave entrances follow one another along the path. They are not deep and run along the slope. Chalk was also mined there.
Hollow road that follows the dry valley through the Heyoule nature reserve (see the highlight). The ideal habitat for many animals that love it, such as the badger, as you also notice when you look around you during the descent.