Battle of Mysunde
1864 CE.
Shown on the map at 54.520°, 9.720°.
The Battle of Mysunde on 2 February 1864 was the first battle between the Prusso-Austrian allied army and the Danish army in the Second Schleswig War. The Prussian vanguard force of 10,000 men attempted to break through and outflank the Danish defenses at the Danevirke, but were repulsed by the fortification garrison and two battalions of the Danish army.
Text from the Wikipedia article Battle of Mysunde (1864), licensed CC BY-SA 4.0.