The Semmering railway was constructed between 1848 and 1854 by some 20,000 workers under the project's designer and director Carl von Ghega born in Venice as Carlo Ghega in an Albanian family. The construction features 14 tunnels (among them the 1,431 m summit tunnel), 16 viaducts (several two-storey) and over 100 stone arch bridges and 11 small iron bridges. The stations and the buildings for the supervisors were often built directly from the waste rock dug out when making the tunnels.