San'yōdō

Running mostly east-west, its eastern terminus, along with those of most of the medieval highways (街道, kaidō), was at Kyoto.

From there it ran west through Fushimi, Yodo, Yamazaki, and Hyōgo; from there it followed the coast of the Seto Inland Sea to Hagi, near Shimonoseki, the western terminus of both the San'yōdō and the San'indō, and very near the westernmost end of the island of Honshū.

As might be expected, the road served an important strategic and logistical role in a number of military situations over the course of the years.

Many daimyō also used this road as part of their mandatory journeys (sankin kotai) to Edo under the Tokugawa shogunate.

The road also served the more everyday purpose of providing transport for merchants, traveling entertainers, pilgrims and other commoners.