http://archaeology.about.com/od/bterms/g/babylon.htm
The Hanging Gardens of Babylon are considered to be one of the original Seven Wonders of the Ancient World. They were built in the ancient city-state of Babylon, near present-day Al Hillah, Babil, in Iraq.
http://answers.ask.com/Society/History/where_was_babylon_located
Babylon (bÄbËÉlÅn) [key], ancient city of Mesopotamia. One of the most important cities of the ancient Middle East, it was on the Euphrates River and was north of the cities that flourished in S Mesopotamia in the 3d millennium B.C. It became important when Hammurabi made it the capital of his kingdom of Babylonia. The patron god of Babylon, Marduk (identical with Bel), became a leading deity in the Neo-Babylonian pantheon. The city was destroyed (c.689 B.C.) by the Assyrians under Sennacherib, and its real spendor belongs to the later period of Babylonia after the city was rebuilt. The brilliant color and luxury of Babylon became legendary from the days of Nebuchadnezzar (d. 562 B.C.). The Hanging Gardens were one of the Seven Wonders of the World. The walls of Babylon, its palace, and the processional way with the famous Ishtar Gate were decorated with colorfully glazed brick. Among the Hebrews (who suffered the Babylonian captivity under Nebuchadnezzar) and the later Greeks the city was famed for its sensual living. Under the rule of Nabonidus the city was captured (538 B.C.) by Cyrus the Great and was used as one of the administrative capitals of the Persian Empire. In 275 B.C. its inhabitants were removed to Seleucia, which replaced Babylon as a commercial center.
http://www.infoplease.com/encyclopedia/history/babylon-ancient-city-mesopotamia.html
So Babylon is near Al Hillah, Babil, in Iraq then?
The Hanging Gardens of Nineveh?
There's a link in the article to her book that was published on the subject last year.
Dalley is a Professor at Oxford, and is one of the few people who can read Assyrian cuneiform. Here's a link to her page at Oxford: