grotta di frasassi, genga, italy. inside one of the most extensive caves in italy. stalactites and stalagmites

formation cave rock geology quail temple terrain caving wadi tree arch ruins cliff canyon trunk carving stalagmite art badlands grotta frasassi genga italy inside one most extensive caves stalactites stalagmites frasassi genga italy europe cave rock nature stone cavern stalagmite stalagmites landmark famous park excursion guide indoors spooky background natural dark darkness lights travel stalactite underground landscape geology mountain canyon wall light tourism limestone rocks natural grotto ancient tree water