Saekimon is also referred to as Kura Shin Ujo. It is on the first floor of the Kugani-Udun in a tunnel-like form, surrounded by the walls and ceiling. There is a curve along this passage which is reminiscent of a maze, and because of this shape, the lighting in the passage was dim even during the day. The historical transition of the Saekimon is believed to be the same as Kugani-Udun (with its construction taking place in 1671, destroyed by fire in 1709, and rebuilt in 1715).It is presumed that the priestesses from Ouchibara passed through the Saekimon to reach the Una for the ceremonies and rituals that took place during the kingdom period.
This building was destroyed in the fire.