The ziggurat is the most distinctive form .
Cities often had large gateways , of which the Ishtar Gate from Neo-Babylonian Babylon , decorated with beasts in polychrome brick , is the most famous , now largely in the Pergamon Museum in Berlin .
The ziggurat is the most distinctive form , and cities often had large gateways , of which the Ishtar Gate from Neo-Babylonian Babylon , decorated with beasts in polychrome brick , is the most famous , now largely in the Pergamon Museum in Berlin .