This mini castle offers a fantastic view that’s designated as one of Japan’s Top 100 Morning Suns

Just 25 minutes north of Mt. Kinka by car is the 407.5-meter-tall Mt. Kojo, where Oga Castle once stood hundreds of years ago. Oga Castle and its surrounding castletown prospered under the leadership of Yorinari Toki, the official constable of Mino Province (modern-day southern Gifu) who moved to the castle from the Gifu-city area in 1535. The castle soon fell as a result of intense fighting with Dosan Saito, leading to turbulent times for Mino Province.

Visitors can imagine what this mountain castle was like back in its heyday as the ruins of stone walls and structures remain standing along the roads climbing Mt. Kojo. At the very top of the mountain is a miniature reconstruction of Oga Castle, which was built by local residents and serves as their symbol.

Visitors can witness an amazing view from where the mini castle stands, and depending on the weather, Mt. Kinka, Ise Bay, Mt. Ibuki, and even the towering buildings of Nagoya can be seen in the distance. This spot is also a popular place to see unkai, or a sea of clouds that form below Mt. Kojo when the conditions are just right.

《Kenkyaku Hiking Course》
Climb about 2.1km from the Mt. Kojo Trailhead to the mountain’s peak (60~90min). Hikers can spot remains of Oga Castle as they make their way to the top.

《Hajikami Course》
This is a short 750m course that begins at the Hajikami Rindo Trailhead and finishes at the peak of Mt. Kojo (takes about 20~30min).

※Both courses have steep sections of road, so please hike with appropriate shoes and clothing, and bring plenty of water.

◇ Officially Designated as One of Japan’s Top 100 Morning Suns
The morning view seen from Mt. Kojo (or Oga Castle Ruins) was officially designated as one of Japan’s Top 100 Morning Suns on April 27, 2021. For those wishing to see the sunrise, the sky begins to brighten up about 30 min before sunrise.

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Basic Information


Kojozan Oga, Yamagata City, Gifu


21min by car from Seki-Hiromi IC to the base of Mt. Kojo

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*** Parking ***
【Mt. Kojo Base】
Large buses: 5 spaces, Normal Cars: 50 spaces

【At the top of Hajikami Rindo Forest Road】
Normal Cars: 15 spaces