The Yodogawa River frequently experienced large-scale floods, causing severe damage to the people living in its basin, so the Meiji government began major renovation work on the Yodogawa River in 1899. A lock gate (completed in 1908) and a wash weir (completed in 1903) were installed at Kema, thereby regulating the amount of water flowing into the old Yodo River (Okawa) and making shipping more convenient. Both buildings are built of brick, with granite cladding at key points. The current lock gate and wash weir were newly built in 1974, but the former No. 1 lock gate and old wash weir from the Meiji era are preserved within Yodogawa River Park and are designated as important cultural properties of the country. I am.