Location
The battle took place south of the ancient town Issus, which is close to present-day Turkish town of Iskenderun (the Turkish equivalent of "Alexandria", founded by Alexander to commemorate his victory), on either side of a small river called Pinarus. At that location the distance from the gulf of Issus to the surrounding mountains is only 2.6 km (2 mi), a place where Darius could not take advantage of his superiority in numbers. Speculation on the location of the Pinarus has taken place for over 80 years. Older historians believed it to be the Deli Tchai river, but historians N.G.L. Hammond and A.M. Devine have made convincing claims that the Pinarus is actually the Payas River, the latter using eye-witness examination of the river, which may not have drastically changed since antiquity. Their evidence is based on Callisthenes' accounts of the measurements of the battlefield and distances marched by both side's armies in the prelude to the battle and distance given by Diodorus after the battle.
Read more about this topic: Battle Of Issus