sitting overlooking the railway tunnels and viaducts in semmering, styria, austria. kalte rinne viaduct. historical monument that

architecture austria austrian bahn breitenstein bridge construction curved engineer engineering europe fortification group heritage hike industry infrastructure kalte krauselklause lower machine medieval mountain nature niedersterreich outdoor polleroswand rail railroad railway range rax raxalpe raxschneeberg rinne schneeberg semmering semmeringbahn steiermark stone styria tourism tourist train transport transportation tunnel unesco valley viaduct