As the mountainous area is mostly on the eastern part of the peninsula, the main rivers tend to move westwards. Two exceptions tend to be the southward-flowing Nakdong River and Seomjin River.Although the Sui army was lured into a entice because of the famed Kogury? commander ?lchi Mund?k, and endured a calamitous defeat on the Salsu (Ch'?ngch'?n)