There is a junior high school past here, in the place where Yanagawa Castle used to be. Construction on the castle began during the Sengoku Period as Yanagawa was a key strategic place in Kyushu. The castle was said to be so well-constructed that it would take three years to breach it, and the canal served well as a protective measure. The tower was built when Yoshimasa Tanaka became the castle’s lord during the Edo Period, and he outfitted the canal for use in the castle’s town. Muneshige Tachibana would develop it further once he became lord.

When the area surrounding the castle site was excavated, the dug soil was heaped on the castle grounds, ensuring it had high elevation. This design ensured that, in the event of flooding, water would flow toward the castle town instead. This was proved by the great Kyushu flood of 2012; while all of Yanagawa was flooded up to the eaves, only the school built on the Yanagawa Castle site seemed to float above it, like an island.

Yanagawa was flooded for over a week. As a result, the canal water became too contaminated to drink, and urgent efforts were made to service the water supply system. People stopped drawing water from the canals, and the waterways became like garbage dumps. Swimming was prohibited, and the children stopped coming to the canals to play. This was the reality for the next 10 years.