You can boulder on sandstone in various places in the Ruhrtal. The largest and most beautiful of these areas is Avalonia, which is located between the towns of Wetter and Herdecke. Daniel Pohl has devoted countless hours to developing the area. With his own hands he cleared the rocks, laid out terraces and decorated the area. Level routes: 3 to 8b+ Exhibition: southeast. Season: All year round. The southeast orientation makes the area ideal for autumn, winter and spring thanks to the fast-drying rock and sunny position.