Mt. Seta and Mt. Kasamatsu are two peaks on a mountain range in Imabari. Although the mountain is neither particularly high or large in area, its location overlooking the Seto Inland Sea and other far higher mountains gives you an exhilarating sense of scale. A hiking trail goes straight up the side of the mountain and along and down a ridge, passing through a temple and the site of an ancient castle.

In the summer of 2008, a forest fire destroyed a large area of woodland on the western side of Mt. Kasamatsu. Visitors to the Towel Museum on that side will no doubt wonder why the mountain looks unusually bare. But pine scrub is reclaiming the rock, and it’s a pleasant environment to walk.

The trail starts at Sendan-ji, an attractive Buddhist temple behind which Mt. Seta rises abruptly. The first leg of the walk is a steep climb up to the inner sanctuary of the temple. You pass through a bamboo forest, which gives way to deciduous trees. The path doglegs up, affording glimpses of the sea and the Saijō Plain. After a considerable climb, there’s a flat area with a small stone sculpture of a Buddha standing on a boat, and a large concrete sculpture of Fudo Miyo holding a sword. Not far beyond this is a flight of one hundred very steep steps up to the inner sanctuary.

The main hall is flanked by abandoned priest’s quarters and a Fudo temple, next to which are some graves, including of Odachi Akeuji, the master of Setayama Castle.

To the right of the graves, the path continues up to the ridgeline. If you take the path to the left, there are some huge boulders, which mark the site of Setayama Castle. In ancient times, Sakurai in Imabari was the seat of the regional government. In the mountains surrounding the Imabari and Saijo Plains, many castles were built to protect the local capital. In the Middle Ages, fierce battles took place in the mountains, including Mt. Seta. The battle over Setayama Castle fought between the Northern and Southern Courts in 1342 is recorded in the Taiheiki, one of Japan’s major historical records. Odachi Akeuji, who supported the Southern Court, was attacked by the ten-thousand strong army of Hosokawa Yoriharu sent by the Northern Court and the Shogunate. After a fierce fight, Akeuji set fire to the castle and committed seppuku with seventeen companions. He was thirty-eight years old. 

There’s a magnificent view from the castle site. Mt. Ishizuchi and the other major mountains in the same range rise up along the Median Tectonic Line that traverses Shikoku. Below them is a large plain of rice fields. To your left, the northern coast of the Seto Inland Sea forms a huge curve.

Doubling back from the castle site takes you to the top of Mt. Seta. From here onwards, there are views over Imabari and the islands and bridges of Shimanami Kaido. You can see the huge pylons of the Kurushima Straights Bridge from here.

Hereafter, the path follows the ridge of the mountain. To your left is the Mt. Takanawa range and to your right, the Seto Inland Sea. In warmer weather, there’s an intense aroma of pine. There are numerous flights of very steep steps. After Mt. Kasamatsu with its pretty little temple, the path goes down steeply to Asakura, an area with a long history of human habitation, with ancient burial mounds.