Inside the Apadana palace ruins are many well preserved bas-reliefs. These show scenes of Persian and Median soldiers marching with their weapons, nobles in a procession and dignitaries from all parts of the empire bringing tributes and gifts to the Persian emperor. Most bas-reliefs in the Apadana are remarkably well preserved, showing a lot of detail. They were not damaged following the Arab conquest of Iran, probably because they were covered by layers of stone and sand. The Islamic conquerors destroyed the faces of bas-reliefs and statues, believing these were pagan idols.