Railroads constructed during turbulent periods and associated with mankind's ugliest deeds. Beginning with the Trans-Pyrenees Railway.
The Harz Mountain Railway in Germany - Europe's longest rail network - which still uses steam locomotives and has a hidden past.
The White Pass and Yukon Railroad over the US-Canada border, which began construction after the Klondike Gold Rush in the 19th century.
The Nordland Line, the longest in Norway. Stretching between Trondheim and Bodo, it was first built to transport the country's iron ore.
The Liverpool and Manchester Railway, which revolutionised rail travel when it opened in 1830, including introducing the first signalling system.
The background to the Tablelands Railway Line in Queensland, which changed the face of the state when it was constructed in the late 1800s.