Jönköping, län (county) of southern Sweden, in Götaland region. It extends southward from Lake Vätter through part of the traditional landskap (province) of Småland. Jönköping is the highest county of southern Sweden, with heights rising above 1,300 feet (400 metres). Its rough terrain is studded with lakes and drained by the rivers Emån, Lagan, and Nissan. Although it is primarily wooded, the län supports rye and oats cultivation and cattle raising. Most manufacturers exploit the timber supply. The main city is Jönköping, the capital, on the southern shore of Lake Vätter. Area 4,345 square miles (11,253 square km). Pop. (2005 est.) 329,297.