The Wurm has dug deep and steeply into the terrain. In some rock faces we find quarries, some with pieces of coal. Coal was already being mined in the Wurmtal valley in the Middle Ages in pits, which we come across again and again in the forest. The mining rights of the Furth mine date back to 1769 and there was a "Fahrkunst", a kind of elevator that was powered by water and transported the workers into the shaft. We can take a break in a historic setting on the village green in Pley. The Antonius Chapel from 1899/1900, a 150-year-old black poplar tree and the stately farmhouses along the Pley road, which have many more years under their belts, compete for the presidency of age. One is the Kuckum feudal estate, where the bailiff of Wilhelmstein resided in 1350. A promontory in the steep Wurmtal valley proved to be a good location for a castle. The Counts of Jülich had Wilhelmstein Castle built here and invaded Aachen from there in 1278.