Mt Kuju &
Mt Taisen

Mt Kuju (Japanese: 久住山) and Mt Taisen (大船山) rise at the heart of the Kuju massif in Oita, a high volcanic plateau shaped by ancient eruptions and long erosion. Their topography is broad and open rather than sharply alpine with wide grasslands, rounded ridges and a chain of gentle summits that form the highest mountain group in mainland Kyushu. The landscape is spacious and airy, with long horizons stretching across the Kuju Highlands and the volcanic basin of Tadewara Marsh lying below. In early summer, the slopes turn vivid pink as the entire range turns into a flowering highland.

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The hike from Chōjabaru is the classic approach, beginning at the edge of Tadewara Marsh where boardwalks cross wetlands fed by volcanic springs. This is the approach I took. From here, the trail enters forest and climbs steadily toward the high plateau. The ascent is long , rising through quiet woodland before breaking into open grassland where the Kuju range suddenly appears in a wide sweep including Kuju, Nakadake (中岳), Taisen and the rounded shoulders of the surrounding peaks. The climb continues toward Bogatsuru, a broad basin of marsh and meadow that feels like a hidden highland valley. Many hikers camp here before exploring the surrounding peaks.

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From Bogatsuru, the trail rises toward the main ridge. The ascent to Mt. Taisen is the more direct climb. It's a steady push up open slopes that lead to a rounded summit with views over the entire Kuju plateau. Mt Kuju is considered the hyakumeizan* point and is one of the highlights of the range, enjoying constant views toward Aso to the south and the long spine of Kyushu’s interior mountains to the north. Kuju’s summit is broad and grassy and in contrast to the steaming volcanic area below. This was one of my favourite hikes in Japan and one I would happily repeat.

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* 100 famous mountains of Japan

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(All information here is based on personal observations and experiences. Check official sources before planning or starting any hikes.)