And King Nebuchadnezzar states the purpose of the Ishtar Gates:

Nebuchadnezzar, King of Babylon, the pious prince appointed by the will of Marduk, the highest priestly prince, beloved of Nabu, of prudent deliberation, who has learnt to embrace wisdom, who fathomed Their (Marduk and Nabu) godly being and pays reverence to their Majesty, the untiring Governor, who always has at heart the care of the cult of Esagila and Ezida and is constantly concerned with the well being of Babylon and Borsippa, the wise, the humble, the caretaker of Esagila and Ezida, the first born son of Nabopolassar, the King of Babylon, am I.

but here is just one tiny daisy out of this wonderful mosaic wall that he commissioned