Kızılırmak River
If one reads the description by Herodotus of the event as a solar eclipse, then based on modern astronomical calculations it can be identified with the solar eclipse of May 28, 585 BC (the Eclipse of Thales), hence yielding the exact date of the battle. For the location of the battle, some scholars assume the Halys River (today "Kızılırmak River") as it was located in the border region between both kingdoms. As Isaac Asimov noted, this would be the earliest recorded eclipse the date of which was accurately determined in advance of its occurrence.