🗺️ Ghost City Mountain (City of Ghosts)鬼城山（鬼ノ城）

Onigashima Mountain is located in the northern part of the Tsusho Plain, with an elevation of about 400 meters, and at its summit stands the Onigashima Castle. Although historical texts such as the "Nihon Shoki" do not record the construction date of the castle, archaeological investigations suggest it was likely built in the latter half of the 7th century. The Japanese army, dispatched to attack the Korean Peninsula, constructed the mountain castle after their defeat at Baekgang Village in 663 AD, in order to defend against the attacks of the Tang Dynasty and the Silla allied forces. This is the most compelling explanation among various legends regarding the construction of Onigashima. Approximately 2.8 kilometers below the summit, a castle wall was erected, featuring four gates and six water gates. Inside, one can see buildings, warehouses, water pools, signal fire towers, and blacksmith workshops, indicating that the castle was quite well-constructed at that time. Currently, visitors can explore the restored corner tower ruins and the gate ruins, and from the west gate, one can enjoy a panoramic view of Okayama City and the Seto Inland Sea, offering a magnificent 360-degree vista. According to legend, Onigashima was once the refuge of the Baekje prince "Onra," who retreated there after being defeated by Kibitsuhiko. It is considered the birthplace of Onra (the demon). Along the walking path that follows the castle wall, there are many strange rocks and boulders named after demons, adding to the enjoyment of the stroll.

There are still many unsolved mysteries in the mountain city to this day. From the restored city gates and other locations, you can see a wide panoramic view. You can also stroll freely along the city walls.