The Spatschlucht was formed around 1800, when the above-ground mining of heavy spar, also known as barite, began. The white spar powder was used as an additive in the manufacture …
A sunken road is a path that has been cut into the surrounding terrain up to 10 metres deep by centuries of use by wagons and livestock as well as run-off rainwater. Wikipedia
Partly asphalted, partly gravel. Nevertheless, a nice, relaxed way along the Ulfenbach. On the other side of the river is the road, here you have your peace.