Siege of Takamatsu
1582 CE.
Shown on the map at 34.693°, 133.822°.
In the 1582 siege of Takamatsu (備中高松城の戦い, Bitchū Takamatsu-jō no tatakai), Toyotomi Hideyoshi laid siege to Takamatsu Castle, which was controlled by the Mōri clan. He diverted a nearby river with dikes to surround and flood the castle. He also constructed towers on barges from which his gunmen could keep up a constant rate of fire and be unhindered themselves by the flooding.
Text from the Wikipedia article Siege of Takamatsu, licensed CC BY-SA 4.0.