The Semmering Railway is the first mountain railway which crossed a high-mountains area and counts therefore as the prototype of railway lines mastering very difficult terrain and considerable altitude difference. The railway was constructed between 1848 and 1854 by some 20,000 workers under the project's designer and director Carl von Ghega. The construction features 14 tunnels (among them the 1,431 m vertex tunnel), 16 viaducts (several two-story) and over 100 curved stone bridges as well as