By Tatsuya Murakami / Yomiuri Shimbun Staff WriterA thatched-roof house stands out among the rice paddies along the river.
This is the birthplace of Mamiya Rinzo (circa 1780-1844), an explorer in the Edo period (1603-1867) who discovered that Karafuto (Sakhalin) is an island by finding the strait that now carries his name.
Next to the house, the Mamiya Rinzo Kinenkan memorial hall features maps of Karafuto and Ezochi (Hokkaido) made with painstaking detail, as well as survey tools and other items from the successful career of this local hero.
Mamiya was born into a farming family, but when he showed a talent for mathematics and other subjects at a young age, the Tokugawa shogunate sent him to Edo to be educated.
In 1799, he made his first visit to Ezochi, accompanying a geographer he was studying under.
At the time, the Tokugawa shogunate needed a better understanding of the unknown north to protect the nation from the southward advance of Russia.
The main exhibit — Kita Ezo-shima Chizu — is a seven-piece topographical map of Karafuto and northeast China. When connected, the entire piece is 14 meters long.
Mamiya presented this map to the Tokugawa shogunate after returning from an 1809 expedition to Karafuto, on which he discovered the Mamiya Strait.
Until then, it was unknown whether Karafuto was an island or a peninsula, making his finding a valuable discovery for the world.
While his expedition to Karafuto lasted only two years, Mamiya spent more than 10 years exploring every corner of Ezo to create Ezo Zenzu — a complete map of Hokkaido and the northern territories.
For this map, he surveyed not only the coasts, but rivers and other inland areas as well. The map also describes important communities in detail.
When Mamiya’s mentor, Ino Tadataka, created Dai Nihon Enkai Yochi Zenzu (Complete maps of Japan’s coastal areas), he used Mamiya’s survey data for the maps of Ezo.
The memorial hall displays a letter written by Ino to Mamiya that reads in part, “I am fond of you like a father.”
The hall displays tools and other items Rinzo used on his explorations, including a hood made of two sheets of thick cotton, a piece of Ezo cloth and a chain for measuring water depth.
“Rinzo’s seriousness and diligent character are what enabled him to accomplish such great things. I hope people dive into the details [of the exhibits], like the information about the land recorded on the maps,” said Akio Kimura, 61, the director of the memorial hall.
■ Mamiya Rinzo Kinenkan
(Mamiya Rinzo Memorial Hall)
The hall was opened in 1993 by the municipal government of what was then Ina town. About ¥160 million was spent on reproductions of state-owned maps, documents and other items. The hall features a video about Mamiya’s life and publications from the Meiji era (1868-1912) to the Showa era (1926-1989).
Address: 64-6 Kamihirayanagi, Tsukubamirai, Ibaraki Prefecture
Open: 9 a.m. to 4:30 p.m. Closed Mondays (Tuesdays if Monday is a holiday)
Admission: Adults ¥100, high school students and people 65-74 ¥50. Free for junior high school students and under, and people 75 and older or disabled