The 58 km section of railway through the Semmering Pass between Gloggnitz and Murzzuschlag built in 1848-54 was part of the Sudbahn, the railway that linked Vienna, capital of the Habsburg Empire, with the principal imperial port at Trieste. It was the first main line railway to pass through one of Europe’s great mountain passes, and in 1998 became the first transport route to be designated a UNESCO World Heritage Site.
There is a monument on a rocky slope near Semmering station to Karl Ritter von Ghega (1802-60), the Venetian engineer who directed the construction of the line. The Semmering Railway includes 16 tunnels, the longest of them being 6 km, and 16 viaducts, one of them 46 m high. A network of hiking trails has been devised to provide walkers with spectacular views of the engineering features of the railway. The UNESCO designation acknowledges that von Ghega provided outstanding technological solutions to the problems associated with the building of railways through mountains, but also that the line, by giving access to an area of great natural beauty, created a new cultural landscape of hotels and other facilities built for visitors. The most imposing of the hotels is the Sudbahnhotel-Semmering on the slope of Kartnerhogel, 2 km north of Semmering station.