Yasui Valley is the spot that best embodies Niyodo Blue in the Niyodo River area. The Valley is famous for the most beautiful autumn leaves in Kochi Prefecture. There are many spots to see in the Valley, including Hiryu Falls, so named because the 30-meter-tall two-stage waterfall looks as if a dragon were wiggling and rising up into the sky, the Suisho Buchi deep water that changes its color to blue or green according to the seasons and the time of day, the 60-meter-tall Shoryu Falls and Mikaeri Falls that can be seen from the road.