Just outside Fontainemore an ancient mule track leads to ‘Gouffre de Guillemore’, a very deep ravine carved through the rock by the Lys torrent, creating a striking waterfall. The Guillemore ravine combines spectacular scenery with strong roots in century-old history. The area was the only passage for several centuries, in fact the ravine was the meeting point between two mule tracks that ascended the Lys valley on its right and left slopes.
Upstream from the ravine, rocks polished by the glacier can even be seen from the regional road; some potholes are also well visible, being characteristic results of erosion caused by the drilling action of a subglacial torrent loaded with debris. A small perfectly circular pothole is present on the right watershed slope and can be identified with ease since it is often filled with water.