Calais (French pronunciation: [ka'lɛ]; in English usually /ˈkæleɪ/ cal-ay, traditionally /ˈkælɨs/; Dutch: Kales) is a town and major ferry port in Northern France in the department of Pas-de-Calais, of which it is a sub-prefecture. Although Calais is by far the largest city in Pas-de-Calais, the department's capital is its third-largest city of Arras. Calais overlooks the Strait of Dover, the narrowest point in the English Channel, which is only 34 km (21 mi) wide here, and is the closest French town to England. The White Cliffs of Dover can easily be seen on a clear day from Calais. Calais is a major port for ferries between France and England, and since 1994 the Channel Tunnel has linked to nearby Coquelles from Folkestone by rail.
Due to its position, Calais since the Middle Ages has been a major port and a very important centre for transport and trading with England.