Siege of the Sogdian Rock
326 BCE.
Shown on the map at 40.400°, 69.400°.
The Sogdian Rock or Rock of Ariamazes, a fortress located north of Bactria in Sogdiana (near Samarkand), ruled by Arimazes, was captured by the forces of Alexander the Great in the early spring of 327 BC as part of his conquest of the Achaemenid Empire.
Text from the Wikipedia article Siege of the Sogdian Rock, licensed CC BY-SA 4.0.