See the clear blue water of a mountain river
The Niyodo River in Kochi, on the island of Shikoku, is known for water so clear and blue that its color has a name of its own: Niyodo Blue. The blue changes with the light and the amount of water, so walk the trails to waterfall pools and gorges, or look down from a chinkabashi, a low bridge with no railings built to let floods pass over it. These spots are in the mountains and easiest to reach by car or taxi from Kochi city; keep away from the water after heavy rain and follow the signs on site.
A small waterfall pool in the mountains where the water falls into a basin of deep, almost glowing blue. Locals have long treated the pool as sacred, home to a water spirit, so you may not swim; you look down on it from a viewing trail. Parking is very limited, so go early or book a taxi tour in advance.
A gorge where clear blue water runs over pale rocks between steep, forested walls. A trail follows the river past small waterfalls to Suisho-buchi, the Crystal Pool, so clear that you can see straight to the bottom. Buses run only a few times a day and the area gets busy in summer and on holidays, so drive or take a taxi and check parking and access before you go.
A narrow gorge with a riverside trail of about 1.3 kilometers out and back, past blue pools and huge boulders to Uryu Falls, about 20 meters high. The rocks get slippery when wet, so wear shoes with good grip. A hot spring inn at the entrance offers day-use baths for a soak after the walk.