Ziggurats are pyramidal structures with flat tops, usually constructed as portions of a temple complex by many groups within the cradle of civilization. While we only have the stone remains today, they were more than just architectural sights to be seen. The bricks were glazed with different colors according to their level and many of the walls sported astrological artwork. At the top of ziggurats were the actual temples. This positioning was advantageous for the priests living and conducting religious sacrifices there because the one stairway up could be easily guarded, thus protecting the ritual and its secrecy.