the stiffe grottos, valle dell'aterno, italy

adorn adorning ancient aquila archaeological archaeology aterno boulder boulders cave caves clastic cult cultural culture dell demetrio europe european fairy geochemical geologic grotte grottos historical history hole holes indoor indoors inside italian italy karstic lime mineral mount mountain mountainous museum natural nature picturesque rock rocky san sediment sediments stiffe stone stones stratigraphic structure structured tourism touristic underground valle vestini wall water