petralona cave, greece- may 25, 2007: ancient karst cave with stalactites and stalagmites, cenote ceiling

cave formation ice caving quail freezing stalagmite blue geology winter stalactite snow reflection rock arctic glacier tunnel petralona greece- may 2007: ancient karst stalactites stalagmites cenote ceiling cave creece ancient stalactites stalagmites cenote ceiling limestone decoration nature cavern rock stalactite stone stalagmite undergroun mountain geology travel underground dark landscape grotto tourism canyon rocks texture old