Seoporu (서포루) is the western sentry post. This post features a wooden structure, known as a poru, built on top of square turret, known as a chiseong.
It is located near Seojangdae (Western Command Post).
All the posts are constructed of brick. They are positioned on turrets that protrude beyond the fortress walls which allowed for easy attacks by artillery on enemies below. There are five sentry posts found at the fortress.
Construction was completed on May 30, 1796.