Kofini dam is the oldest man-made dam still in use. It was constructed in 1260 B.C.E. It is located on the Lakissa River in Greece.[1][2][3]
References
^Axman, M; Krocova, S (2020). Protection of population and water retention developments. IOP Conference Series: Earth and Environmental Science. Vol. 444. IOP Publishing. p. 012001.