The whole palace complex was torched. The tradition is that a drunken Alexander was urged to do it by an Athenian hetaira, specicially to revenge Xerxes' burning of the Acropolis, but I think that his real motive was far more calculating and cold-blooded. Persepolis was the palace above all others associated with Persian royalty, and specifically with the descendants of Darius the Great. By burning it, Alexander was broadcasting to the world that their power was broken, and in the most spectacular manner that he could have devised. That he wished his action to be interpreted as an assault on the house of Darius, and not on Persian traditions per se, is demonstrated by the very ostentatious honour he paid to the tomb of Cyrus, located some twenty five miles to the north of Persepolis, at Pasargadae.