Channel Tunnel

The Channel Tunnel is a 50.45-kilometre (31.35 mi) rail tunnel linking Folkestone, Kent, in the United Kingdom, with Coquelles, Pas-de-Calais, near Calais in northern France, beneath the English Channel at the Strait of Dover. At its lowest point, it is 75 m (250 ft) deep below the sea bed, and 115 m (380 ft) below sea level. At 37.9 kilometres (23.5 mi), the tunnel has the longest undersea portion of any tunnel in the world, although the Seikan Tunnel in Japan is both longer overall at 53.85 kilometres (33.46 mi) and deeper at 240 metres (790 ft) below sea level. The speed limit for trains in the tunnel is 160 kilometres per hour (99 mph).

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