Tsūjunkyō Bridge (通潤橋) 通潤橋
National Treasure since 2023, the first among engineering works: it has irrigated 100 hectares since 1854.
Futa Yasunosuke, intendant of the village of Yabe (now Yamato), had it built in 1854 to bring water to a plateau that had none. It is about 78 metres long, 6.6 wide and about 21.3 high, with an arch radius of 28.1 metres; inside it run 119 metres of stone pipe that are part of a network of about 42 kilometres, fed by the Sasahara River six kilometres away, which still irrigates about a hundred hectares of the Shiraito plateau. The water discharge that made it famous serves to flush sand out of the pipe, and it is the only stone arch bridge in Japan able to do so. In 1960 it was designated 重要文化財, an Important Cultural Property, and in 2023 国宝, a National Treasure, the highest grade in the Japanese register: it is the first civil engineering work in the country to receive it.
Kumamoto
通潤山荘, 浜町, 通潤橋前
