buracas do casmilo at condeixa - portugal

buracas casmilo geological ancient geology archaeological cave complex entrance mouth opening system cavern cliff face side coimbra condeixa erosion formation grassy slope green heritage site hidden caves hillside historic karst topography limestone moss covered mountain mountainous natural arch habitat landmark wonder nature portugal prehistoric rock outcrop shelter structure wall rocky terrain rugged landscape stone path vegetation weathered wilderness area portugal nestled featuring multiple openings moss-covered formations cloudy day