Battle of Reynogüelén
1536 CE.
Shown on the map at -36.647°, -72.455°.
The Battle of Reynogüelén took place between Spanish conquistadors and Mapuche soldiers, thought to have occurred near the confluence of the Ñuble and Itata Rivers, in Chile. This battle is an antecedent of the Arauco War.
Text from the Wikipedia article Battle of Reynogüelén (1536), licensed CC BY-SA 4.0.