The mountain railway winds downstream along precipitous cliffs. The National Park is surrounded by 2,000-meter mountains.
Okuoi is located in the northern part of Shizuoka, where part of the upstream region of the Oi-gawa River, which flows into Suruga Bay, is located. Surrounded by mountains as high as 2,000 meters, the region has been designated as a prefectural national park, thereby preserving the entire area, and keeping its rich nature intact and safe from modern development.
The Ikawa Dam, which dams the upper section of the Oi-gawa River, and many other artificial reservoirs, including Lake Ikawa-ko and Lake Hatanagi-ko, provide scenic spots which attract many visitors, especially during the peak season for the autumn-colored maple trees. The Sesso Valley complements the surrounding virgin forests, running for about 13 kilometers along the river and winding its way downstream through the precipitous cliffs. You can catch a glimpse of its beauty through the windows of the mountain railway, the Ikawa Line, which is the only Alternate Biting Tooth (Abt) system in the country. On the Ikawa Line, a private rail line, you can enjoy the magnificent scenery of the Sekinosawa Bridge, which rises 100 meters above ground level, the highest of all the private rail systems in the country.
The Sesso-kyo-onsen Hot Spring is situated between the Ikawa Dam and the downstream Nagashima Dam, and the Sumata-kyo-onsen Hot Spring area is spread over the Sumata Valley. A steam locomotive connects JR Kanaya Station and Senzu, the entrance to Okuoi, a ride that takes about 70 minutes. The train runs once a day, and this steam locomotive is particularly popular among holidaymakers.
[Rail] 1h to Shizuoka Station by JR Tokaido Shinkansen Line. 30 min from Shizuoka to Kanaya Station by JR Tokaido Line, and 1h 10 min from Kanaya to Senzu Station by Oigawa Line.
[Rail] 2h from Shin-Osaka to Shizuoka Station by Shinkansen.