Sansha Pass

The Sansha Pass [山下山量 さんしゃ・さんりょう] is a mountain pass on the southern Taiyū Alps connecting the western Yamanokan portion of what is now Mikei Prefecture to the coastal eastern region, Yamanoshi. 
The route which ran through the pass was a very ancient one, dating to the early Chisō period when it once connected Namema and Mizuno Provinces. The road was developed further into the medieval era to better facilitate trade between Sanzama and Kōsori Provinces, and was of great economic importance due to its connection to the Hongiryō dōryō highway.