The only place where we get to see the Tower of Babel in Fate the tallest landmark in Babylon map, and the city itself looks like to be covered in gold. It's located at where Gilgamesh' Ziggurat was. One could say Nebuchadnezzar II made his own version of Ziggurat. And then Draco swallowed this place with her mega Tsunami. With a wave big enough to even drown the Tower of Babel.