The pass on the ancient Tōsandō highway was described as early as the 8th century, in the Nihon Shoki, as Yamato Takeru went through the pass during his journey in eastern Japan.
Tōsandō |
Iwanuma is at the convergence of two ancient roads, the Tōkaidō (via the Pacific coast) and the Tōsandō (inland route), both originating in the Kansai region.
During the Ritsuryō period, roads from Kinai to the Tagajō were divided into two: the Tōkaidō eastern sea road (via Nagoya, Hamamatsu, Tokyo and Mito) and the Tōsandō eastern mountain road (via Gifu, Shiojiri, Takasaki and Utsunomiya).