Yagi Castle was built by Naito Sadafusa an ally of Ashikaga Takauji who planned to overthrow the Kamakura Shogunate. After the establishment of the Muromachi Shogunate, the Naito served as vassals under Hosokawa Morimoto as lord of Settsu, Tosa, Sanuki, and Aki, the Tanba. In 1431 the title of Ruler of Tanba was given to Naito Nobushige. Due it's close proximity to Kyoto and sitting at the entrance to the Tanba region Yagi Castle was involved in many of the power struggles from the Onin War up and until the region was pacified by Akechi Mitsuhide for Oda Nobunaga as the first step in conquering the Tanba region. There is actually no evidence of the Akechi Mitsuhide battle having taken place, so it's possible that there was some internal treason or plot to bloodlessly surrender to the inevitable.
Yagi Castle is also well known for the Christian warlord Naito Joan who was a successful warlord and supported missionaries in Japan. Joan was absent from the castle when it was attacked by Mitsuhide. After the fall of the Naito, he resided with the Maeda in Kanazawa but was eventually banished with Takayama Ukon after the Tokugawa became Shogun. For this reason (successful Christian daimyo) it is surmised that some of the history around Naito Joan and the castle may have been manipulated or scrubbed from history.
After Mitsuhide built nearby Kameyama Castle, Yagi Castle may have still functioned as a branch castle (note the great views of the basin!). There are plenty of legends that Mitsuhide actually escaped Hideyoshi's forces and one of those suggest he hid in Yagi Castle living on gold he buried here while he was daimyo of Kameyama Castle. Some treasure hunters still think there may be gold buried at Yagi-jo today.
Yagi Castle is a huge sprawling castle complex and is known as one of the Three Biggest Yamajiro of Tanba (丹波三大山城). For some reason is not very well known and tends to be skipped over by most of the major castle publications in Japan. Of the "Tanba 3", Kuroi Castle and Yagami Castle are arguably more famous.
The route up to the honmaru is well maintained and sign posted but you need to work a little harder to find some of the farther reaches of the castle. From the bottom of the mountain, at the entrance to the hiking trail, you'll find many terraced areas that were the homes of retainers. Thanks to many switchbacks, the trail takes you to the top of the mountain without being too steep or challenging. The trail ends right at the honmaru/ninomaru entrance and the first major stone wall ruins. The honmaru has some stunning views of the surrounding plains and you can easily see why a giant castle was built here. Take the small narrow trail around the back of the honmaru to find another stone wall segment. If you look around the sides of the honmaru you will see a great many stones strewn about. At one point the whole honmaru was fortified with stone walls.
From the Ninomaru there are trails going north and west that will take you along ridges literally covered in stepped flat areas that were baileys of the original castle. From this point there are no maps and few useful signs. A couple of the farthest reaches have horikiri and stone wall segments as well. There are a number of trails that link up to other trails and go down different areas of the mountain but there are few signs. In fact, I was stopped twice by groups of hikers who wanted to ask ME about the trails. At one point along the western ridge coming back from the stone wall and horikiri I became unsure of the trail because it looked steeper than I remembered. After turning around and looking for signs of a trail I found a pink ribbon tied to a tree (signs of a trail on this mountain!). I felt reassured and started following the pink ribbons... until I found myself back at the same horikiri and stone wall again! Well, I did find the right trail back, but it does show how someone with a poor sense of direction (yes, me) can lose the trail.
|English Name||Yagi Castle (Tanba)|
|Castle Condition||Ruins only|
|Historical Period||Pre Edo Period|
|Access||Yagi Sta. (Sanin line), 10 min walk to trailhead|
|Visitor Information||mountain trails, open anytime|
|Time Required||240 mins|
|Coordinates||35° 3' 39.10" N, 135° 31' 24.10" E|
|Added to Jcastle||2022|
|Admin Year Visited||2022|
|Admin Visits||May 8, 2022|
|Friends of JCastle|
|Jokaku Horoki: Yagi-jo|