The Iwaoboki Sluice Gate, together with the Kushiro River, was constructed as part of a flood control project implemented from Taisho 10 (1921), triggered by the Taisho 9 (1920) Kushiro River flood, and was completed in Showa 6 (1931).
Originally, it was something made for the purpose of timber transport on the Kushiro River, but it is said that this sluice gate has never been opened since its completion because it yielded the main role of timber transportation to the Senmō Main Line, which opened around the same time. Nevertheless, its charming appearance continues to be loved by many people as a picturesque central figure of the Kushiro Wetland. From near the sluice gate, Mt. Meakan and Mt. Oakan can be seen well.
Especially in winter, if the weather is good, you can see the scenery beautifully.
The sunset seen from here is also superb! When you are looking at the entire wetland dyed in sunset colors, you might become in a romantic mood.
People who say that they have not yet seen the wetland's sunset, why don't you definitely try going... I think you will surely be satisfied.
New Sluice Gate and Sluice Gate Park. In place of the deteriorated sluice gate, the construction of the Iwaoboki New Sluice Gate was commenced from Showa 60 (1985) and was completed in Heisei 2 (1990). After this, the development of an administration building equipped with sluice gate operating functions and a museum etc., waterways, and ponds and gates etc. to finely adjust the water flow volume is planned to be carried out, and the area around the sluice gate is being planned for parkification as a parkland to enjoy the river, utilizing the historical landscape.