rocky landscape in teufelsschlucht nature reserve, trail between eroded rock formations

canyon cliff concept ecosystem eifel environment erosion europe exploration forest formation geologic geology green groove ground high hiking hill land landscape massif massive mountain nature old park path plateau ravine reserve rock rocky route rural sandstone staircase stairs stairway stone summer tourism trail travel tree valley wall wilderness woods teufelsschlucht eroded formations moss-covered stones abundant trees illuminated sun background sunny day irrel germany