Battle of Las Tres Acequias
1814 CE.
Shown on the map at -33.646°, -70.735°.
The Battle of Les Tres Acequias, fought during the Chilean War of Independence, occurred near San Bernardo on 26 August 1814. The confrontation occurred between the two factions of Carrera and Bernardo O'Higgins, resulting in a defeat for O'Higgins that would in turn lead on to the defeat of the nationalists by the royalist forces at the battle of Rancagua a month later.
Text from the Wikipedia article Battle of Las Tres Acequias, licensed CC BY-SA 4.0.