Inō Tadataka: Surveying Japan on Foot

At 17 Inō was adopted into the prosperous Inō family of Sawara, now part of Katori. For decades he ran the family business, expanding its sake brewing and rice trading, until he retired at 49 and left for Edo to study astronomy. The family home still stands on the bank of the Ono River and is a National Historic Site. The present building dates from 1793, so he lived in it only two years. The memorial museum that once stood in the grounds now occupies a newer building across the street.

Visitor guidance: The house and the memorial museum stand on opposite sides of the street in Sawara, Katori.

Inō's first survey set off on 11 June 1800, with five members. By then he was a pupil of the astronomer Takahashi Yoshitoki. On leaving he prayed at Tomioka Hachiman, then stopped at the calendar bureau in Asakusa for a drink at Takahashi's house, and was seen off by relatives at Senju. The shogunate had approved the survey but granted no funds, so the first journey was paid from Inō's own pocket. The shrine was founded in Fukagawa in 1627.

Visitor guidance: A working shrine in Koto ward, Tokyo.

The crossing to Hokkaido was slow: contrary winds kept them eight days at Mimmaya before the boat could sail, and they finally walked to Hakodate from Yoshioka. Inō spent eight nights in Hakodate for procedural reasons and used the time to climb Mount Hakodate and measure a bearing. The survey was meant to begin charting the Hokkaido coast, where Russian ships had come to open trading houses.

Visitor guidance: Reachable on foot, by bike or by the Mount Hakodate cable car.

From Hakodate the team surveyed along the coast, pacing out distances by foot and taking astronomical observations at night. They reached Nishibetsu, in today's Bekkai in far northeast Hokkaido, on the 7th day of the 8th lunar month. It was salmon season and locals said they could supply neither boats nor men to go on to Nemuro, so Inō turned back. The expedition lasted 180 days, 117 of them in Ezo, and the first survey covered 3,244 km on foot.

Location precision: The record names Nishibetsu, in today's Bekkai, but not an exact spot; the pin marks the centre of Bekkai.

Earlier surveys had started from different city gates: Takanawa on the Tokaido and Yotsuya on the Koshu road. The tenth survey was meant to link every highway to one origin, Nihonbashi. Inō, now 71, took part from the 3rd to the 19th day of the 2nd lunar month of 1815. By then his teams were large: 19 people by the fifth expedition, and over 13,000 km in 914 days on the eighth, mostly in Kyushu.

Visitor guidance: The bridge is in Chuo ward, central Tokyo.

Inō died on 17 May 1818, with his great map unfinished. His team completed it in 1821, and maps based on his work were still in use in 1924. Before he died he said he wanted to rest beside his teacher Takahashi Yoshitoki, so his grave lies at Genkū-ji in Taitō ward, Tokyo, alongside Takahashi's. It was designated a National Historic Site in 1928.

Visitor guidance: A temple in Taitō ward, Tokyo.

After his death Inō was one of 37 people honoured at Hokkaidō Shrine in Sapporo as kami, spirits associated with the government's pioneering effort to settle and develop Hokkaido. The honour fits the island's place in his story: his first survey, in 1800, set out mainly to begin charting the Hokkaido coast, and it ended in the far northeast, at Bekkai.

Visitor guidance: Open shrine grounds in Sapporo.