Czersko Polskie roller dam, Bydgoszcz

The Jaz Czersko Polskie is a roller dam located in the area of the mouth of the Brda river to the Vistula river in Bydgoszcz. Belonging to the district of Czersko Polskie, it is the initial stage of the 294.3 kilometres (182.9 mi) long inland navigation route Vistula-Oder waterway, connecting the rivers Vistula and Oder. It is the oldest roller dam in Poland. This unique Polish hydrotechnical construction has been maintained in an operative order since the beginning of the 20th century.

Dam data from Wikidata (CC0) plus curated additions. Summary from Wikipedia (CC BY-SA).