Medieval camino graffiti in Germany?

When training for my very first Camino, while living in Germany, I remember the THRILL of seeing the yellow arrow for "Jakobsweg" on a post for the first time - it became my very first photo from the Camino, even though I still had months to go before actually taking that first step.
This carving drives home how far the Camino de Santiago stretches, both through time and distance.
It's fun seeing the artist's attempts to draw the shell a couple of times before he/she nails it!