Osaka no seki (the Osaka Barrier) (逢坂関)

Osaka no seki (the Osaka Barrier, 逢坂関) was the border between Yamashiro Province and Omi Province. It is also written as 相坂関, 合坂関, 会坂関 (all are pronounced as Osaka no seki).

Since both the Tokaido Road and the Tosando Road (later called the Nakasendo Road) passed through the Osaka no seki, it was an important center of transportation. Its importance can be seen in the fact that, from the middle of the Heian period (810), it was counted as one of the Sangen, or three major barriers. The other two major barriers were Fuwa no seki (Fuwa Barrier), Suzuka no seki (Suzuka Barrier) and Arachi no seki (Arachi Barrier) instead of Osaka no seki being one of the three major barriers until the early Heian period.

Location
The actual location of the barrier is not known since the area has been built over with roads in the modern years. However, from descriptions of relations between Seki-dera Temple, which stood near Choan-ji Temple in Osaka 2-chome, and Osaka no seki recorded in the Sarashina Nikki (Sarashina Diary) and the Ishiyama-dera Records, it is presumed that the barrier was located near Choan-ji Temple. There is also a monument inscribed 'Site of Osakayama Barrier' beside the Osakayama Checkpoint (to the east of Otani Station on the Keihan-Keishin Line), which is located next to the National Route 1 in Otani-cho, Otsu City, Shiga Prefecture.

History
It was firstly established in 646, but was later abolished in 795. Later, the defenses of Heian-kyo (a former name of Kyoto) were rebuilt, and in 857, on orders from the authorities, the barrier was re-established together with Oishi and Ryuge in Omi Province. In the Daijokanpu (official documents of the Daijokan, Grand Council of State) issued on December 3, 895, people holding the fifth rank or higher and relatives of the Emperor were forbidden to go out of the Kinai region and Osaka no seki was considered as the east boundary. The barrier soon became a rest station for travelers, and FUJIWARA no Michitsuna's mother, the author of Kagero Nikki (The Gossamer Years), records resting there in 970 while crossing the Osaka Pass.

From the Kamakura period, Osaka no seki held a strategically important position to the east of Kyoto, and starting in the period of the Northern and Southern Courts (Japan), it was managed by Enjo-ji Temple, which began charging a toll. However after the warrior monks of Enjo-ji Temple destroyed the pass under the jurisdiction of Nanzen-ji Temple in 1367, Osaka no seki and Shugu-kawara no seki (both in Yamashina Ward, Kyoto) were burned down by Sadayo IMAGAWA, the Samurai-dokoro tonin (Governor of the Board of Retainers). After the above incident, Osaka no seki was rebuilt but was temporarily no used along with Otani no seki (Otani Barrier) when a new pass was built in Otsu for the reconstruction of Ise-jingu Shrine in 1460 and it is believed that the Muromachi bakufu wanted to gain control of the pass under the jurisdiction of Enjoj-ji Temple for financial reasons. Osaka no seki continued to exist after that and there is a record of Yoshimochi ASHIKAGA passing through the barrier when he went to visit Ise-jingu Shrine in 1418.

Appearances in literature
Osaka no seki is also known as an utamakura (a word, usually a well-known place, used in classical Japanese poetry to allow poets to express ideas concisely), and features in two poems in Hyakunin Isshu (One Hundred Poems by One Hundred Poets).

"After all, people leaving or returning, people parting, friends and strangers, all meet at Osaka no seki"Semimaru (Poem No. 10)

"In the middle of the night, the imitated crow of a rooster may fool some, but the guards of Osaka no seki can never be deceived"Sei Shonagon (Poem No. 62)

Also, 'Osaka, Suma no seki (Suma Barrier), Suzuka no seki' are mentioned in the section 'On Barriers' in "Makura no soshi" (the Pillow Book).