In the time of Leonidas , in 480 BC. , the pass was a narrow path (about 12 meters wide) under the hill, which the Greek soldiers attempted to strategically exploit to block the outnumbered Persian army. Today the passage of Thermopylae reaches from 1.5 to 3 kilometers wide, due to the deposits at the mouth of Sperchios .
The hot springs, from which the pass takes its name, still exist on the slopes of the hill.
Finally, as Constantinos Cavafy mentions with the phrase "Honor to those who in their lives defined and guarded Thermopylae", the word "Thermopylae" means belief in principles and values, high goals.