River Asopus at Thermopylae

This image depicts a view of the river Asopus, at Thermopylae.  According to Herodotus, who provides the history of the battle between the Greeks and Persians in 480 BCE:  "The river Asopus ... flows for awhile along the foot of the hills." 

This was the general area of the Persian camp.

Credits

Quoted passage from Herodotus, Histories, 7.199

Image online, courtesy Livius.org