Kampen runs along the left bank of the IJssel (near to its mouth). It was prosperous in the Middle Ages through its trade in herring. The town belonged to the Hanseatic League. Its trading relationships extended throughout the Baltic Sea. Declining in the 16C (wars and silting of the IJssel), it was reduced, with the closure of the Zuiderzee, to the role of a river port. Kampen has nevertheless preserved a large number of old houses and monuments from its prestigious past.