is a Japanese geographical term.[1] It means both an ancient division of the country and the main road running through it.[2] It is part of the Gokishichidō system.[3] It was situated along the central mountains of northern Honshu,[4] specifically the Tōhoku region.
This term also refers to a series of roads that connected the of each of the provinces that made up the region.
The Tōsandō region encompasses eight ancient provinces.[5]
After 711 AD, Tōsandō was understood to include the Musashi province.[7]