The Hanging Gardens of Babylon

The Hanging Gardens of Babylon, also known as the Hanging Gardens of Semiramis, near present-day Al Hillah, Babil in Iraq, are considered to be one of the original Seven Wonders of the World. They were built by the Chaldean king Nebuchadnezzar II around 600 BC. He is reported to have constructed the gardens to please his sick wife, Amytis of Media, who longed for the trees and fragrant plants of her homeland Persia.The gardens were destroyed by several earthquakes after the 2nd century BC.

The lush Hanging Gardens are extensively documented by Greek historians such as Strabo and Diodorus Siculus. Through the ages, the location may have been confused with gardens that existed at Nimrud, since tablets from there clearly show gardens. Writings on these tablets describe the possible use of something similar to an Archimedes screw as a process of raising the water to the required height.

The Hanging Gardens of Babylon are perhaps the most mysterious of the seven wonders. They are remarkable in that they compose the only wonder whose very existence has been very seriously called into question. That’s right, it appears uncertain at best that the hanging gardens ever really existed; the alternative being that they were some sort of hypothetical flight of fancy from the minds of some of the more poetic historians of ancient times.

Reference :
http://en.wikipedia.org/wiki/Hanging_Gardens_of_Babylon