Seonamgangnu (Southwestern Pavilion), or Hwayangnu, is located at an elevated position that allows for surveillance of large areas of the fortress. This elevated feature is known as a gangnu.
Construction started on April 16, 1796. It was completed three months later on July 20, 1796. The sign hanging above reads “Hwayangnu,” which literally means “the pavilion south of the mountains in Hwaseong.”
In times of peace, the building was used as a place of rest. During times of war, it was used as a command post by troops stationed in the immediate area.
Seonamgangnu is located at the end of Yongdo (Passageway) that runs along Mount Paldalsan.
There are four gangnu present at Hwaseong Fortress.