A long, 19-km hike in a part of the forest that I had never seen before. A fairly difficult trail to follow as a lot of the paths are pretty overgrown, but this makes for a more adventurous atmosphere than on the other carefully maintained trails of the forest. The terrain was fairly undulating, with some good climbs at times. Plenty of quarries that were used for the paving stones of Paris. And, in the final section of the hike, lots of tracks with unusual names such as the road of happiness, of mystery, of lovers, of beauty, of seduction, etc. It makes you wonder what went on here in the past…