stone staircase on hiking route in groove of a rocky slope or walls of eroded rock formations

canyon cave cliff concept ecosystem eifel environment erosion europe exploration forest formation geologic geology green groove high hiking hill land landscape massif massive mountain natural nature old park path people plateau ravine reserve rock rocky rough route rural sandstone stone summer texture tourism trail travel tree valley wilderness woman woods staircase slope walls eroded formations female hiker trees background sunny day teufelsschlucht irrel germany