AT Herand there is a fine nature trail. It starts at the parking lot between the water-driven saw and the mill in the town centre. A main attraction along the trail is the ledge that has a honeycomb pattern along its whole surface. This pattern occurs under overhangs and other places where the bedrock is dry, also in rainy weather. Geologists call this phenomenon “tafoni” (from Corsican). These cavities develop when salt, that occurs in the bedrock, carves channels when the water evaporates and the salt deposits out. This process loosens thin flakes of stone. The pitting occurs as such flakes gradually carve farther and farther into the bedrock. Where it gets wet, the salt will be washed away and the bedrock does not develop cavities.