The Channel Tunnel, (also referred to as the Chunnel) is a 50.5-kilometre (31.4 mi) undersea rail tunnel linking Folkestone, Kent in England 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 metres (250 ft) deep. At 37.9 kilometres (23.5 mi), the Channel Tunnel possesses the longest...