This sprawling restaurant in a riverside gorge near Ikeda-ko gets an estimated 200,000 annual visitors (!), paying tribute to the 1967 birthplace of nagashi-sōmen (flowing noodles). Sōmen (thin wheat-flour noodles) spin around tyre-shaped table-top tanks of swiftly flowing 13°C water; catch the noodles with your chopsticks and dip them in sauce to eat. Lots of fun and ultra-refreshing on hot days.
It's such a pilgrimage site for many Japanese that there's even a Shintō shrine here.
Teishoku (from ¥1340) come with onigiri (rice balls), miso soup and grilled masu (trout), which swim (along with sturgeon) in pools around the restaurant.