Histories
Herodotus
Herodotus. Godley, Alfred Denis, translator. Cambridge, MA; London: Harvard University Press; William Heinemann, Ltd., 1920-1925 (printing).
When the Pisistratids proposed terms of surrender, they would not listen but contrived defenses such as rolling down boulders onto the barbarians when they came near the gates. For a long time Xerxes was at a loss, unable to capture them.