Nagatoro River Rafting — Arakawa Gorge Rapids

Nagatoro (長瀞) sits where the Arakawa River cuts through a crystalline limestone gorge, creating Class II–III rapids over exposed rock formations. The traditional river activity is line-rafting (ライン下り) — wooden boats piloted by skilled boatmen using long poles to navigate rapids and standing waves. The 6-kilometer, 20-minute ride combines gentle drifting past layered rock cliffs with sudden drops and splashing rapids that soak passengers.

The exposed rock formations — designated a National Natural Monument — show millions of years of geological history in tilted sedimentary layers called the 'Nagatoro Schist Belt'. The combination of whitewater excitement and geological spectacle makes Nagatoro Tokyo's closest authentic river-rafting destination. Peak season (spring snowmelt and post-typhoon autumn) brings higher water and more aggressive rapids; summer offers tamer family-friendly conditions.