Versturzhoehle Riesenburg, natural karst cave ruin of Frankendolomite, geotope, natural monument, near Engelhardsberg, district of Markt Wiesenttal, Upper Franconia, Franconian Switzerland, Franconia, Bavaria, Germany, Europe

bavaria caves cave central europe deserted dolomite rock dolostone empty europe famous place franconian dolomite franconian switzerland franconia franken fraenkische schweiz geotopes geotope german federal republic germany karst cave ruins karst cave ruin karst caves karst cave markt wiesenttal middle europe mineral nutrients minerals mineral natural landmark natural monuments natural monument natural nobody no one no people oberfranken place of interest rock layer rock stratums rock stratum rocks rocky rock sedimentary rocks sedimentary rock sedimentation sediments sediment sights sight southern germany south germany sueddeutschland tourist attractions tourist attraction travel photography travel uninhabited upper franconia wiesenttal wiesent valley