Onami-ike

Onami-ike, whose name means great wave pond, is the largest and most beautiful of the crater lakes that stud the Kirishima highlands above Kagoshima. Cradled in an ancient volcanic crater at around 1,200 metres, its still, deep-blue water is ringed by wooded slopes and reached by one of the most rewarding day hikes in the Kirishima-Kinkowan National Park - a walk that combines the serenity of a mountain lake with the drama of an active volcanic landscape.

The lake itself is a striking sight: a near-circular body of water filling a crater almost two kilometres across, its surface changing colour with the light and sky from steel grey to vivid cobalt. Unlike some of the region's more acidic volcanic ponds, Onami-ike supports fish and is fringed by forest, giving it a tranquil, almost alpine character that contrasts with the barren, sulphurous slopes of the peaks nearby. The scene is at its most beautiful when framed by spring azaleas or autumn colour.

The classic experience is the circular hiking trail. Beginning near the Ebino Eco Museum Center, the route climbs steadily to the crater rim and follows a ridge high above the water, offering ever-widening panoramas. From the higher points the view opens across the whole Kirishima range and, on clear days, all the way to the smoking cone of Sakurajima and the blue expanse of Kinko Bay far to the south - one of the great long-distance vistas of Kyushu. Keen hikers often combine the loop with an ascent of Mount Karakuni, the range's highest peak.

The visiting experience is that of a genuine mountain walk. The full circuit takes a couple of hours and involves real climbing on rocky, sometimes steep ground, so sturdy footwear, water and weather-appropriate clothing are essential; the reward is a sense of wild highland beauty that easy roadside viewpoints cannot match. Because this is an active volcanic area, sections of trail can close due to gas or eruptive activity, so it is important to check current conditions at the visitor center before setting out.

Late spring, when the Kyushu azaleas bloom, and autumn, when the slopes turn, are the finest seasons, while clear summer days give the best long views; winter can bring snow and closures. Early starts reward hikers with calmer air and clearer skies, and the lake is often at its most mirror-still in the morning.

Getting there means first reaching the Ebino Kogen highland, most easily by car via the Kirishima scenic roads or by seasonal bus from the Kirishima and Kobayashi areas; the trailheads lie near the Ebino visitor center. For travellers who want more than a viewpoint - who want to walk into the volcanic heart of the Kirishima mountains and stand above one of its loveliest crater lakes - the Onami-ike loop is among the most memorable half-day adventures within reach of Kagoshima.