The Battle of Kunersdorf occurred on 12 August 1759 near Kunersdorf immediately east of Frankfurt an der Oder. Part of the Third Silesian War and the wider Seven Years' War, the battle involved over 100,000 men. An Allied army commanded by Pyotr Saltykov and Ernst Gideon von Laudon that included 41,000 Russians and 18,500 Austrians defeated Frederick the Great's army of 50,900 Prussians.
The terrain complicated battle tactics for both sides, but the Russians and the Austrians, having arrived in the area first, were able to overcome many of its difficulties by strengthening a causeway between two small ponds. They had also devised a solution to Frederick's deadly modus operandi, the oblique order. Although Frederick's troops initially gained the upper hand in the battle, the sheer number of Allied troops gave the Russians and Austrians an advantage. By afternoon, when the combatants were exhausted, fresh Austrian troops thrown into the fray secured the Allied victory.
Wikipedia https://en.wikipedia.org/wiki/Battle_of_Kunersdorf
Official Website http://www.kunowice1759.pl/
Address 69-100, Poland
Coordinates 52°21'8.923" N 14°37'31.236" E