los burros ravine with its roman aqueduct excavated in rock in sierra de albarracin, teruel

landscape sky teruel spain channel cave rock history ruin gea roman aqueduct hill old attraction ancient nature stone europa travel building view mountain destination town spanish architecture historical heritage village historic scenery desert picturesque beautiful sierra albarracin water hoyas shafts specus cella excavated clay hills burros gorge libramentum spiraculi culture