Cross the river then take a few steps in front of you to reach the barrier which towers over the fossilized Tufière. Go to the bottom of the face by the small winding path. Once down there, notice the inlayed holes in the quarry. Some are empty, and others are filled.
They are in fact the imprints of fallen trees on the Tufière, when it was still active. Two cases occur: in the first case, the trees wrapped in the tufa end up rotting and disintegrating leaving holes now visible in the front of the face.
In the second case where the holes are filled, the trees are fossilized. Trapped in the tufa thousands of years ago, the trunks have since then been preserved by the absence of air. The wood began to rot when the face was opened.
At the end of the face, go right to see the ruins of the quarryman’s old shelter situated 50m away. Be careful do not continue down the path, but return to the small canal where the water arrives and turn right until you reach the Tufière spring following the green and yellow markings.