The city's proximity to England has made it a major port for centuries. It is the principal ferry crossing point between England and France, with the vast majority of Channel crossings being made between Dover and Calais. Companies operating from Calais include Sea France (currently in liquidation and P&O Ferries. The French end of the Channel Tunnel is situated in the vicinity of Calais, in Coquelles some 4 miles (6.4 km) to the west of the town. Calais possesses direct rail links to Paris, 148 miles (238 km) to the south. More than 10 million people visit Calais annually.
From medieval times, English companies thrived in Calais. Calais was a particularly important centre in the production and trade of wool and cloth, which outweighed the costs of maintaining the town as part of England. In 1830 some 113 manufacturers were based in Calais and the St Pierre suburbs, the majority of whom were English. There are still two major lace factories in Calais with around 700 looms and 3000 employees. The town exports in the early 20th century were lace, chemicals, paper, wines, especially champagne, spirits, hay, straw, wool, potatoes, woven goods, fruit, glass-ware, lace and metal-ware. Principal imports in the early 20th century included cotton and silk goods, coal, iron and steel, petroleum, timber, raw wool, cotton yarn and cork. During the five years 1901–1905 the average annual value of exports was £8,388,000 (£6,363,000 in the years 1896–1900), of imports £4,145,000 (£3,759,000 in 1896–1900).
As a fishing port, Calais has several notable fishing markets including Les Delices de la Mer and Huitriere Calaisenne on the Boulevard La Fayette, the latter of which is noted for its oysters, lobster and crabs from Brittany. The Emile Fournier et Fils market on the Rue Mouron sells mainly smoked fish including salmon, trout, herring and halibut