The Nabatean burial tombs, Mada’in Saleh site, Saudi Arabia.
The stepped motive of asecending and descending steps is seen in many cultures, even in the native american indians (step pyramid and reversed step pyramid) and in the Indian drinking wells. (See earlier blog post) . I think it symbolizes mans ascention and descention of spiritual consiousness, wether in the chakra system or on a greater scale in the precession of the stars getting closer and further away from the centre of the universe. (mans fall from eden/ jacobs ladder up and down the steps etc etc)