A pleasant walk at one hour from Paris to discover an old sandstone quarry.
The trail of the marshals is a forest path in the park of the Valley of Chevreuse. The walk is nice, you walk in the middle of old quarries of sandstone and many panels inform you about lives of the workers at that time. You will become unbeatable on the different stages of the creation of sandstone. From this walk you can reach the Cernay Abbey and the famous waterfalls of Cernay aren't very far either. It's a good way to discover this part of the Chevreuse Valley.