Borsippa is an archeological site in Babylon Province, Iraq. The ziggurat, the "Tongue Tower," today one of the most vividly identifiable surviving ziggurats, is identified in the later Talmudic and Arabic culture with the Tower of Babel. However, modern scholarship concludes that the Sumero-Akkadian builders of the Ziggurat in reality erected it as a religious edifice in honor of the local god Nabu, called the "son" of Babylon's Marduk, as would be appropriate for Babylon's lesser sister-city.
Borsippa was an important ancient city of Sumer, built on both sides of a lake about 17.7 km southwest of Babylon on the east bank of the Euphrates.
An inscription of Nebuchadnezzar II, the "Borsippa inscription," tells how he restored the temple of Nabu, "the temple of the seven spheres," with "bricks of noble lapis lazuli." that must have been covered with a rich blue glaze, surely a memorable sight. Archeologists have determined that Nebuchadnezzar's ziggurat encased the ruins of a smaller tower from the second millennium BCE. When it was completed it reached a height of 70 meters, in seven terraces; even in ruin it still stands a striking 52 meters over the perfectly flat plain.
(source : wikipedia)