According to The Guardian, the fate of the Hanging Gardens of Babylon is somewhat of a mystery. The legendary gardens were one of the Seven Wonders of the ancient world, and the most common explanation for their disappearance is an earthquake that struck the region around the second century.
King Nebuchadnezzar created the Hanging Gardens as a present for his wife, according to the legend. While there are many references to these fantastic gardens in the historical record, most occur after the destruction of the Gardens, and no archaeological evidence has ever been found where they were said to have stood.
Some historians argue that the mud-brick construction of the time would not have left physical evidence after the destruction of the wonder, while others suggest the true site may have become obscured when the rivers of Babylon changed their course. One possible explanation for this discrepancy is that the legend of the Hanging Gardens became intertwined with an actual construction elsewhere in the region. Archaeologists discovered the remnants of an extensive terraced garden near the ancient city of Nineveh in the Assyrian Empire, possibly built by Sennacherib much earlier than Nebuchadnezzar's reign. After conquering Babylon in 689 B.C., Sennacherib often referred to Nineveh as "the new Babylon," possibly contributing to the confusion.