Urajio - Urajio

...It is 999m above sea level, and National Route 20 passes through it. It is located at the watershed between the Tenryu River and the Shinano River, and the name of the pass is said to have been derived from the fact that it is the terminus of the surface salt (omotejio) transported inland from the Pacific coast and the back salt transported from the Japan Sea coast. It is a key transportation and military point connecting the Suwa and Matsumoto basins, and has often been a battlefield since ancient times.

*Some of the terminology that refers to "urashio" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…標高は999mで，国道20号線が通過している。天竜川･信濃川両水系の分水嶺にあたり，峠の名は太平洋岸から内陸部に運ばれる表塩（おもてじお）と，日本海岸から運ばれる裏塩の終点にあたることから名付けられたといわれる。諏訪･松本両盆地を結ぶ交通･軍事の要衝で，古来からしばしば戦場となった。…

※「裏塩」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報