Mt. Chausuyama is a mountain located on the border between Aichi and Nagano Prefectures, with its highest point at 1,415.2 meters on the Aichi side, making it the tallest peak in Aichi Prefecture. The mountain lies within the Tenryu-Okumikawa Quasi-National Park and features the Chausuyama Highlands, which extend between Mt. Chausuyama and Mt. Hagitaro (1,358 meters) to the southwest. The area developed as a year-round outdoor recreation destination combining natural alpine scenery with seasonal activities.
The highlands hold natural significance for their diverse seasonal landscapes including white birch forests, grasslands, and alpine flora. The area is home to Japan's highest moss phlox field, with approximately 400,000 phlox plants covering a 22,000-square-meter site on Mt. Hagitaro's slopes. These flowers bloom in six colors including pink, white, sky blue, and lilac from mid-May to early June during the Shibazakura Festival. The highlands mark where Aichi Prefecture's autumn foliage appears first, with seasonal colors reflecting in quiet mountain pools. The summit offers panoramic views of the Southern Japanese Alps.
Visitors can hike well-maintained trails to the summit, taking approximately 30 minutes from the Information Center or 20 minutes via the eastern route. The mountain supports hiking from spring through fall with different seasonal experiences including phlox viewing, summer greenery, and autumn colors. Activities include go-karting, mountain biking, canoeing, and fish-catching during warmer months. The area hosts Aichi Prefecture's only ski resort during winter, offering skiing, snowboarding, and sledding with conveyor belt walkways for easy access. Night activities include illuminated phlox gardens and stargazing opportunities.
Mt. Chausuyama is located in Toyone Village, approximately 1 hour and 20 minutes by car from the Shin-Tomei Expressway Shinshiro Interchange. The mountain has no nearby train stations, making car access the primary transportation method. Admission to hiking trails is free, though the ski resort, seasonal festivals, and activity facilities charge separate fees.