Spartan/Thespian grave in Thermopylae?

[Giannis K. Hoplite]

The territory of Thermopylae was Persian after the battle of 480bc,however the Persian army moved quickly from there. There must have been some treatment for the Persian but also for the Greek dead there. The Greeks would most probably left to be urried by the medized Greeks,if not for anything else,to clear the only road between North and South Greece.
Further more,the monument with the famous inscription seems to suggest that they were burried somewhere there.And the fact that Spartans decades later moved the supposed corpse of Leonidas to Sparta also suggests that they were not cremated and that there was a real grave somewhere. After all,the Athenian tumulous in Marathon stands still in the plain and the Athenian bones have een found in the hill. But nothing of the Spartans and Thespians. The place has been excavated and hundreds of arrowheads were found on the hill,but I don't know if thy actually dug deeper in the hill.
Any input?
Khaire
Giannis