![The Sensui-kyo Bridge over the Tonda-gawa River](https://nankikumanogeo.jp/eng/wp-content/uploads/sites/2/pic_geosite46.jpg)
Because the Tonda-gawa River repeatedly flooded, it was necessary to build a strong bridge that would not be damaged by the floodwaters. The Sensui-kyo Bridge has less obstacles such as rails for less damage. It is said that they imitated the bridge in Shimanto-gawa River in the Shikoku district.