Turku, Swed. Åbo, city (1998 pop. 170,931), capital of Western Finland prov., SW Finland, at the mouth of the Aurajoki River on the Baltic Sea. The center of the fertile agricultural region of SW Finland, it is also the country's largest winter port and an important industrial city. Its manufactures include shipbuilding, machinery, food, and textiles; tourism is also important. Known as the 'cradle of Finnish culture,' Turku is among Finland's oldest cities. Swedish Crusaders landed on the site in 1157. It was the seat (1220) of the first bishop of Finland, and the capital of Finland until 1812. The national university was in Turku from 1640 to 1827, when a fire destroyed almost the entire city and the university was moved (1828) to Helsinki. The Treaty of Åbo, by which Sweden ceded part of SE Finland to Russia, was signed in the city in 1743. The great cathedral was begun in the early 13th cent. The 13th-century castle, burned in 1614 and restored in 1961, is now a historic museum. Turku has a Finnish university (founded 1917) and a Swedish university (founded 1918).