West Gate Site is one of the important gates of this mountain city, the only city gate located at the top of the mountain, and there are relics such as door steps, door pivot foundation stones, stone walls and guard rooms. The door steps are paved with stone slabs, with 5 steps, 3.3 meters long and 2.4 meters wide. On both sides of the door steps are the door pivot foundation stones cut from granite, having round stone nests on them, with diameter of 16 cm, bottom diameter of 11 cm and depth of 8 cm, which are used for installing and rotating door leaf. Behind them, there are two stone walls nearly one-meter high, and each has a concave building with wedge-shaped stone barriers on three sides, covering an area of about one square meter, which is actually the site of the guard room where soldiers stood guard at that time.

Wunvshan Mountain City, in terms of city site layout, wall masonry and wall stone processing, pioneered the construction of mountain city field by the Koguryo nation, and had a great influence on the architecture of the later Koguryo mountain cities and even the architecture technology of Northeast Asia.