huge stones stacked forming a mound next to a dirt path at entrance to teufelsschlucht nature reserve

concept decorative ecosystem eifel environment erosion europe exploration foliage footpath forest formation garden geologic geology giant green groove ground heavy hiking land landscape mountain natural nature old outdoor park path reserve rock rough route rural stone summer texture tourism trail travel tree vacation valley wild wilderness wood woodland woods huge stones stacked forming mound next dirt entrance teufelsschlucht leafy trees background sunny spring day irrel germany