like soy sauce from Choshi, but also products from the Tōhoku region, in order to save time and to avoid risk in the open sea. With the advent of the railway in the 19th century major shipping on the Tone quickly declined, and inland ports such as Noda, Sekiyado, now part of Noda, Nagareyama, and Sawara, now part of Katori diminished in importance. Today the river has several dams that supply water for more than 30 million inhabitants of metropolitan Tokyo and large-scale industrial areas such as the Keiyō Industrial Zone. Rafting and kayaking The Minakami onsen area in Gunma Prefecture is near the source for the Tone River and during the Spring snow melt period, April - June, the river provides consistent grade 4 rapids (on the International Scale of River Difficulty) over a stretch. The river provides some of the best white water rafting and kayaking in Japan. The snow melt swells the river to grade 4 in spring; in the summer it is a gentle grade 2. The Momijikyo section has 7 grade 3-4 rapids for and is long in total. Cycling The Tone River is home to Japan's longest car free cycling path. At over 220km long the Tone River Cycling Road 利根川サイクリングロード starts in Shibukawa City, Gunma and runs all the way to Choshi City, Chiba. The total route is over 230km but the final 10km or so into Choshi is on a road. The remaining 220km is on detached cycling paths high up on the river bank with great views of mountains while in Gunma and large rice fields and agriculture as you approach the ocean. Image gallery References External links Rivers of Gunma Prefecture Rivers of Ibaraki Prefecture Rivers of Saitama Prefecture Rivers of Chiba Prefecture Rivers of Japan