Osakafuritsusayamaikehakubutsukan Museum

Sayama Pond, built in 616 CE during the Asuka period, is Japan's oldest dam-type reservoir, watering downstream farmland for 1,400 years. Its historic renovations involved figures like the Nara-period monk Gyoki, Kamakura-period Chogen, and Edo-period Katagiri Katsumoto. Today it serves flood control more than irrigation. The Sayama Pond Museum, opened in 2001, tells this 1,400-year history of the reservoir and its engineering, centering on massive relocated relics like the pond's embankment structure and the wooden pipes once buried to channel water to the fields. The building itself was designed by renowned architect Tadao Ando.