Aizu Nishi Kaidō

The Aizu Nishi Kaidō (会津西街道) was a 130 km (81 mi) pre-modern highway constructed in Edo period Japan.

[1] With the establishment of Aizu Domain, the daimyō Hoshina Masayuki (1611-1673) called for the construction of a road to connect his castle with the Ōshū Kaidō, which was the main route north-south from the Tokugawa shogunate's capital of Edo (modern-day Tokyo).

It was also political, as the daimyō (regional ruler) of Aizu were required to travel back-and-forth to Edo on alternative years with a large retinue under the sankin-kōtai system and needed a well-maintained road with suitable post stations for rest and resupply along the route.

The road Hoshina Masayuki created was marked with ichirizuka distance markers to facilitate travel.

When the dam burst in 1723 during torrential rains, 1200 people were killed by the flood in downstream of Utsunomiya.