Shio no Michi (塩の道) was an old kaidō, or road, in ancient Japan and was used to transport salt from the ocean to the inland central Honshū. In the Middle Ages, salt was brought both from the Sea of Japan and the Pacific Ocean to Shinano Province for processing. The road leading from the Sea of Japan to Shinano Province was called the Chikuni Kaidō (千国街道), whereas the road leading from the Pacific Ocean was called the Sanshū Kaidō (三州街道).

Stations of the Chikuni Kaidō

On the Echigo Province side of the route, it was called the Itoigawa Kaidō, but on the Shinano Province side, it was called Chikuni Kaidō. The Sawado-juku and Sano-juku pair and the Ida-juku and Imori-juku pair each essentially functioned as one post station.

Niigata Prefecture

Nagano Prefecture

Stations of the Sanshū Kaidō

The salt was initially carried from Mikawa Bay by boats traveling up the Yahagi River and its tributary, the Tomoe River. From Toyota, it was carried by horse, marking the start of the Sanshū Kaidō.

Aichi Prefecture

Nagano Prefecture