[dredmorbius]

And, researching just now: there are a few canals in Japan, though even a modern listing is short:

https://en.wikipedia.org/wiki/Category:Canals_in_Japan

Among the earliest is the Takase River canal, in Kyoto, 9.7 kilometers, dug in 1611. Most of the remainder date to the 19th or 20th centuries.

https://en.wikipedia.org/wiki/Takase_River

The Tatsumi Canal was constructed in 1623, 11 km.

https://en.wikipedia.org/wiki/Tatsumi_Canal

Contrast the UK:

https://en.wikipedia.org/wiki/Canals_of_the_United_Kingdom

https://en.wikipedia.org/wiki/List_of_canals_of_the_United_K...