Osaka Prefectural Sayamaike Museum
Sayamaike, Japan’s oldest dam-style reservoir, was built 1,400 years ago. Over the centuries, a range of historical figures took part in its repairs, including Gyoki in the Nara period, Chogen in the Kamakura period, and Katagiri Katsumoto in the Edo period. The Osaka Prefectural Sayamaike Museum preserves and displays materials related to civil engineering techniques used in these repairs and flood control.
The whole building was designed by Tadao Ando, so the moment you walk in, you get that signature style—smooth concrete, water features, and beautiful light and shadow.
There are lots of exhibits about Sayamaike and ancient waterworks engineering. It might sound a little heavy, but it’s actually presented in a really easy-to-understand way.