The Ziggurat (ジッグラト jiggurato?) is an alternate layer of reality where Hand Shakers battle. To be able to access it directly is to become a Hand Shaker. Once a hand shaker pair lost they will be unable to stand within the Ziggurat. Another way to be kicked out is if you are 1000 ft away from the general battle area as stated by Makihara. But this fact is not applicable to Yukiya Araki the main protagonist in W'z as he is able to enter the Ziggurat dimension by his own will and bring whoever he wants into the Ziggurat dimension.
The Ziggurat is mainly the same as the normal world except that it has vast colours and designs upon one another and any damage done there will not be reflected on the real world.