South of Oberfeistritz the rail line crosses the Feistritz River then meanders southwest over hill and dale to Weiz. Here the train is seen crossing the Grub Viaduct. This is the longest viaduct on the route at 275 metres (902 feet) in length. Constructed during 1909 with 13 arches of "iron concrete" this was the first use of reinforced concrete in Austria.