The Tunnel, Liverpool & Manchester Railway, mid 19th century.

UNITED KINGDOM - JUNE 10: Coloured aquatint showing the inside of the tunnel built near Liverpool on the Liverpool & Manchester Railway. Constructed under the guidance of chief engineer George Stephenson (1781-1848), the line laid between Liverpool and Manchester was the world's first intercity railway. The building of the railway was a major civil engineering project. As well as this tunnel, 63 bridges and an embankment over the peat bog at Chat Moss, near Manchester, had to be built. The opening ceremony on 15 September 1830 included a procession of eight locomotives, including Robert Stephenson's (1803-1859) famous 'Rocket'. (Photo by SSPL/Getty Images)