rock formations. tassili n'ajjer national park. algeria, africa

desert deserted dune dunes rock rocky stone stony sandstone erosion arch arched natural window mountain mountains sand formation double arches wind weathered fissure sahara wadi bouhadian tadrart tadrart algeria algerian africa djanet tamezguida tassili tassili n#39aph39#ajjer n#39aph39#ajjer national park nature natural erg geology geological landform barren terrain heat tourism travel venture shadow wilderness