<Tr> <Td> 35.912 mi </Td> </Tr> <Tr> <Td> Mileages from Castle Hill Tunnel Portal Mileages to terminals measured around terminal loops </Td> </Tr> <P> The Channel Tunnel (French: Le tunnel sous la Manche; also nicknamed Chunnel) 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). </P> <P> The tunnel carries high - speed Eurostar passenger trains, the Eurotunnel Shuttle for road vehicles--the largest such transport in the world--and international goods trains . The tunnel connects end - to - end with the LGV Nord and High Speed 1 high - speed railway lines . </P>

Where does the chunnel cross the english channel