SAITAMA, Feb 02, 2026 (News On Japan) - Nagatoro in Saitama Prefecture, widely known for its dynamic river rafting experiences, offers a very different way to enjoy the area during winter, allowing visitors to take in the dramatic Iwadatami rock formations while staying warm aboard so-called “kotatsu boats.”
While Nagatoro is typically associated with fast-paced river descents, the winter months bring calmer conditions as water levels drop and the river flow becomes gentler, making it possible for boats to move slowly and smoothly downstream, with passengers seated around a heated kotatsu.
Commenting on the experience, Fukuyama noted how warm the kotatsu felt, while a boatman explained that the calm and tranquil sections of the river are known as “toroba,” adding that the name Nagatoro comes from the fact that such stretches continue for a long distance in this area.
From the boat, passengers can also see Nagatoro’s most famous geological feature, the expansive Iwadatami rock formation on the right bank, which the boatman pointed out as the area’s best-known sight.
The rocks, which are believed to have originally formed some 20 to 30 kilometers underground before being pushed to the surface by crustal movements, are considered extremely rare, and the Nagatoro area has been designated a National Place of Scenic Beauty and Natural Monument.
The winter kotatsu boat ride offered sweeping views and a relaxing atmosphere, leaving visitors feeling warmed both physically and mentally as they drifted through one of Japan’s most striking natural landscapes.
Source: TBS
