Battle of Fredrikshamn
1790 CE.
Shown on the map at 60.520°, 27.180°.
The battle of Fredrikshamn was an attack by the Swedish archipelago fleet on their Russian counterparts near the town of Fredrikshamn (Hamina) during the Russo-Swedish War (1788–1790).
Text from the Wikipedia article Battle of Fredrikshamn, licensed CC BY-SA 4.0.