Oike, A Natural Spring Pond
The clear Oike spring wells up from the ground deep in the old-growth forest on the northern side of Mt. Kurodake in the Kuju Mountain Range. Each day, more than 20,000 tons of pure spring water gushes from the spring. The water naturally stays at around 12°C throughout the year, 6–7°C cooler than that of the surrounding lowland areas, due to its relatively high altitude of 850 m above sea level.
Oike’s location and geology, in the heart of a forest of deciduous broad-leaved trees within a volcanic mountain range, mean that mineral-rich water stored underground wells up through the porous volcanic soil. The result is a spring with exceptional water quality that has been designated one of the Selected 100 Exquisite and Well-Conserved Waters by the Ministry of the Environment.
Local people have used water from Oike for drinking and agricultural purposes for many years. Today, to preserve the spring’s naturally fresh water, the Yufu Tourist Association collects donations for cleaning and conservation work.