Chikugo River, which runs through the Chikugo plain, starts its journey from the rim of Mount Aso, making its way through four prefectures (Oita, Kumamoto, Fukuoka and Saga), nourishing each along the way, before emptying out in to the Ariake Sea. At 143m long, this river is the largest in Kyushu. This river is known as one of Japan’s three great rivers, along with the Tone river in Kanto, and the Yoshino river in Shikoku. An abundance of calm, pure waters, the Chikugo river is Kyushu’s finest gift from mother nature, and a symbol of the region's culture and history. Nicknamed ‘the birthplace of culture’, the riverbed is dotted with historical sites. The natural beauty of the landscape is also partly thanks to the river. Though it was once considered a violent river, water control measures and the completion of upstream dams, including the large Chikugo dam, constructed in 1984, have now made the water levels of the river adjustable. This has brought calm to its flow while enabling the water supply to be used for agriculture.