What the Ottomans called Yerebatan Sarayi (Sunken Palace) is in fact a 6C Byzantine underground cistern that supplied water to the palace of the emperor Justinian. Clever plays of light coupled with the background dripping of water add to the theatrical aspect of a tour along the walkways of this cistern, where a forest of superbly restored columns emerge from the water and are reflected in it. Historiated Corinthian capitals and strange Medusa heads from an early pagan temple lend an additional sense of mystery to the overall scene.