cave of valporquero. the cave of valporquero is located on the southern slope of the cantabrian mountains, north of the province

adventure ancient background beautiful boulders cave cavern corridor dark deep earth erosion europe exploration explore formation geological geology ground inside interior interiors karst landmark landscape leon light limestone mountain mysterious national natural nature park rock shapes spain speleology stalactite stalactites stalagmite stalagmites stalagnate stone subterranean tourism travel tunnel underground water