Since the mountainous region is totally on the jap Section of the peninsula, the principle rivers often movement westwards. Two exceptions would be the southward-flowing Nakdong River and Seomjin River.
However the Sui Military was lured into a entice because of the famed Koguryŏ commander Ŭlchi Mundŏk, and suffered a calamitous defeat within the Salsu (Ch'ŏngch'ŏn) River. It is claimed that only 2,seven-hundred in the three hundred,000 Sui troopers who had crossed the Yalu survived to search out their way back, as well as Sui emperor now lifted the siege of Liao-tung Fortress and 파라곤솔루션 withdrew his forces to China suitable. Yang Ti continued to send out his armies towards Koguryŏ but all over again with no achievement, and in advance of extended his war-weakened empire crumbled." ^