島田宿大井川川越(Shimada inn town Oi River crossing): You could’ve gotten stuck by this river bank for days and weeks 150 years ago

Even horses can cross eight ri(=31 km/19.5miles) of Hakone, but the Oi River is hard to get over in any way. (Translation from Wikipedia. I added the conversion to mileage) 

This part of Shimada is probably considered as an extension of Shimada inn town. However, there is no accommodation. When the water level of Oi river increases to the impassable point, people had to stay in this area, along with Shimada inn town. 

As we explore, I will explain the reason why it was so hard to cross this river. 

This is Tsukamoto family residence. The residence was built by Omura domain of Kyushu, today’s central Nagasaki prefecture during Edo period. Tsukamoto family provided meals, took over paperwork and arranged logistics to cross the river for Omura domain. 

Up until 1870, there were no bridges or boat services over Oi River. 

On the right there used to be the 9th station for 川越人足(Kawagoshi ninsoku: special porters for crossing rivers). There used to 10 Kawagoe ninsoku, and each group had own station. On the left beyond the house, there used to be a buckwheat noodle shop back in Edo period. 

Kawagoe ninsoku 6th station is on the left. Shimada city museum annex is on the right side. 

There were many reasons why Tokugawa government did not build a bridge or hire sailors for boats. These porters were one of them. Until recent years, people believed that the very reason for not building a bridge over Oi River was for military defense. 

The third station is on the left. 10th station is the house on the right, more toward the center of this photo, followed by the 2nd station(It’s hard to see because it’s right next to the 10th). Beyond the third station, there is Nakama no Yado(peers’ station). This station was used as a conference and recreation center, and a hangout place for young workers. 

仲間の宿(Nakama no Yado).

There was Tachiai-yado ruins. Tachiai-yado was like a break room for Tachiainin. A Tachiainin was an information guide or a navigator to and from Shimada inn town and crossing the river. 

This is 札場(Fudaba), where river-crossing workers get paid.

There was Kawaai the street of Fudaba, there was 川会所(Kawakaisho), which was the administrative office. The officer of Kawakaisho measured the depth of the river each day, determined opening/closing of river crossing, fees etc. 

The Kawakaisho building, built in 1856, has been relocated several times, and is now 3 houses west of where was the original place. Shimada city is hoping to relocate back to this original place. 

This stand recreated what Edo-time food stands used to be. It is actually in front of buckwheat noodle restaurant. Where a tall tree stands, is the current place of Kawaaisho building. 

Kawaaisho building stands here. 

Beyond this, there is an old dyke called 島田大堤(Shimada Oh-tsutsumi). This dyke consist of dyke and irrigation canals. It was completed by mid 1600s, in order to prevent flooding from Oi River. Since its completion, production of rice tripled. 

This is the fifth station of Kawagoshi ninsoku. 

By the way, some of these buildings are now being used as a workshop, exhibitions and a meeting place. 

After we passed by the first station of Kawagoshi ninsoku, we see this dyke called Segi. Until late 19th century, beyond this point, it was the river. 

This board has a Ukiyoe picture of Yoshitsuya Utagawa’s “Minamoto Yoritomo’s Procession Crossing Oi River”, published in 1863. Although the title says “Yoritomo Minamoto”, who was the founder of Kamakura shogunate in late 12th century, the artist drew river crossing of Iemochi Tokugawa, the 14th shogun of Tokugawa shogunate, on his way to Kyoto. 

Now we are crossing Oi river.

Well, today there is a bridge, on Shizuoka prefectural R-381, not far from here. 

I have been scattering the reasons of not building a bridge over this river around. 

Making a concise summary, the reasons were 1) technology wise, it was nearly impossible to build a bridge on a winding, fast-running river with lots of thick layers of sands that easily destroyed the foundations, 2) established local businesses of crossing rivers opposing boat-ride businesses from outside local areas, and 3) costs of rebuilding a bridge multiple times(the average lifetime of a wooden bridge was 20 years in those days without frequent damages by natural disasters). 

I might have missed a few more reasons. 

You can get to Oigawa Kawagoshi ruins by bus from JR Shimada station, and get off at Mukaijima Nishi Kawagoshi Kaido Iriguchi bus stop. Even if you walk from Shimada station, it’ll be like 25-30 minutes. 

The next stop is Kanaya inn town, on the west bank of Oi River. 

References(Translation by use of AI, partially edited by me): 

About Oi River Kawagoshi Site. Shimada City Museum.(In Japanese:大井川川越遺跡について　島田市博物館) https://www.city.shimada.shizuoka.jp/shimahaku/docs/kawagoshi-iseki.html (In Japanese only. Accessed in 1/29/2026)

Connecting Bridges: a Civil Engineer’s Analysis of the Charm of History of Bridges. Hiroshi Matsumoto. Journal “Water Cultyre” No.47, Milan Water Culture Center(In Japanese: つなぐ橋：土木技術者が読み解く　橋の歴史の魅力　松村博　機関誌「水の文化」47号  ミツカン水の文化センター) https://www.mizu.gr.jp/kikanshi/no47/01.html (In Japanese: Accessed in 1/29/2026)

Learning from the Past: Crossing the Oi River(Part I). Oigawa, Shizuoka, Japan. Shimada City Tourism Division. https://oi-river-trip.com/en/the-best-of-things-to-do/crossing-the-oi-river-part1/ (Accessed in 1/30/2026)

Oi River. Wikipedia.com. https://en.wikipedia.org/wiki/%C5%8Ci_River (Accessed in 1/29/2026)

Shimada-Hulu Oi River Kawagoshi Site. Wikipedia.com. (in Japanese:島田宿大井川川越遺跡　ウィキペディア https://ja.wikipedia.org/wiki/%E5%B3%B6%E7%94%B0%E5%AE%BF%E5%A4%A7%E4%BA%95%E5%B7%9D%E5%B7%9D%E8%B6%8A%E9%81%BA%E8%B7%A1 (In Japanese. Accessed in 1/29/2026)

Stroll map(of Tokaido). AMZ Environment Design Research Office Ltd. shizuoka-tokaido.biz/en/map/index.html (Accessed in 1/30/2026) 

Yoritomo Minamoto’s Procession Crossing Oi River. Yoshitsuya Utagawa. Cultural Heritage Online. The Agency for Cultural Affairs. (In Japanese:頼朝公大井川行列図　歌川芳艶文化遺産オンライン) https://bunka.nii.ac.jp/heritages/detail/279250 (In Japanese only. Accessed in 1/29/2026)