Calais (/ˈkæleɪ/ CAL-ay, traditionally /ˈkælɨs/; French pronunciation: ​[kaˈlɛ]; 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. The population of the metropolitan area at the 1999 census was 125,584. 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.