This “Kaiser Karls Bettstatt” are just two quartzite rocks near Monschau-Mützenich next to the German-Belgian border. There’s an interesting legend around it that says that Charelemagne once slept on one of the large rocks when he got lost there. His servant was sleeping on the smaller rock. As it was a bit cold, the servant offered Charlemagne a cap, i.e. a “Mütze”, but Charlemagne didn’t want it and said “Mütze nicht” (no cap). That’s where the name of the village Mützenich comes from.