Battle of Quillagua
1879 CE.
Shown on the map at -21.620°, -69.606°.
The Battle of Quillagua was a battle of the War of the Pacific that occurred on October 10, 1879. It was the first ever land battle between the Peruvian and Chilean infantry.
Text from the Wikipedia article Battle of Quillagua, licensed CC BY-SA 4.0.