Today is the 25th anniversary of the formal opening of the Channel Tunnel, a 31.4 mile long, mostly undersea rail tunnel connecting the city of Calais in northern France with the English town of Folkestone, Kent. The commemoration ceremony was a diplomatic coup but an engineer's nightmare: they had to run a train carrying Queen Elizabeth II and a train with French President Francois Mitterand toward each other... on the same track. Plus: a look at how the designers of the world's longest road tunnel - the Laerdal Tunnel in Norway - made sure drivers wouldn't get bored and nod off on their 15 mile journey underground.
The Channel Tunnel: 20 fascinating facts (Telegraph UK)
10 Strange Structural Engineering Marvels: Laerdal Tunnel (HowStuffWorks)
