At any rate, the rising power of Silla controlled the area by 505. Capitalizing on the territory's strategic potential, Silla set up various mountain fortresses in the area to control movement in and out of western Korea. Control of transit through the area would have gained even greater importance after Silla's 553 seizure of the Han River valley on the western side of the mountains. At this time the low Haneuljae pass near Poam Mountain was probably the favored crossing, in contrast to the higher Mungyeong Saejae pass which came into favor in the Joseon period.