Battle of Mount Lycaeum
226 BCE.
Shown on the map at 37.457°, 21.975°.
The Battle of Mount Lycaeum (or Lykion) was fought between Sparta led by Cleomenes III and the Achaean League commanded by Aratus. It was the first major battle of the Cleomenean War. The battle occurred at Mount Lycaeum on the border of Elis and Arcadia and ended in a Spartan victory.
Text from the Wikipedia article Battle of Mount Lycaeum, licensed CC BY-SA 4.0.