The man that showed the Persians the alternate route (the Anopaia path) was a local, named "ephialtis".(translates to "nightmare") Its still used today to call someone a traitor.
When scouts came to Dieneces, a warrior that had distinguished himself in battle, they told him that the Persians were so many that their arrows hid the sun. His response was: "Good, we shall fight in the shade.".
A statue of Leonidas and a cenotaph mark the spot today.


The King with half the East at heel is marched from lands of morning;
Their fighters drink the rivers up, their shafts benight the air.
And he that stands will die for naught, and home there's no returning.
The Spartans on the sea-wet rock sat down and combed their hair.

A.E. Housman