slopes of rock formations, fallen log on hiking trails, stones covered with moss, abundant trees in background

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 slopes formations fallen log trails stones covered moss abundant trees background teufelsschlucht view viewing point sunny day irrel germany