The approach to the Garden sloped like a hillside and the several parts of the structure rose from one another tier on tier... On all this, the earth had been piled... and was thickly planted with trees of every kind that, by their great size and other charm, gave pleasure to the beholder... The water machines [raised] the water in great abundance from the river, although no one outside could see it.
Diodorus Siculus

Fruits and flowers... Waterfalls... Gardens hanging from the palace terraces... Exotic animals... This is the picture of the Hanging Gardens of Babylon in most people's minds. It may be surprising to know that they might have never existed except in the minds of Greek poets and historians!

Location
On the east bank of the River Euphrates, about 50 km south of Baghdad, Iraq.

History
The Babylonian kingdom flourished under the rule of the famous King, Hammurabi (1792-1750 BC). It was not until the reign of Naboplashar (625-605 BC) of the Neo-Babylonian dynasty that the Mesopotamian civilization reached its ultimate glory. His son, Nebuchadnezzar II (604-562 BC) is credited for building the legendary Hanging Gardens. It is said that the Gardens were built by Nebuchadnezzar to please his wife or concubine who had been "brought up in Media and had a passion for mountain surroundings".

While the most descriptive accounts of the Gardens come from Greek historians such as Berossus and Diodorus Siculus, Babylonian records stay silent on the matter. Tablets from the time of Nebuchadnezzar do not have a single reference to the Hanging Gardens, although descriptions of his palace, the city of Babylon, and the walls are found. Even the historians who give detailed descriptions of the Hanging Gardens never saw them. Modern historians argue that when Alexander's soldiers reached the fertile land of Mesopotamia and saw Babylon, they were impressed. When they later returned to their rugged homeland, they had stories to tell about the amazing gardens and palm trees at Mesopotamia.. About the palace of Nebuchadnezzar.. About the Tower of Babel and the ziggurats. And it was the imagination of poets and ancient historians that blended all these elements together to produce one of the World Wonders.

It wasn't until the twentieth century that some of the mysteries surrounding the Hanging Gardens were revealed. Archaeologists are still struggling to gather enough evidence before reaching the final conclusions about the location of the Gardens, their irrigation system, and their true appearance. Some recent researchers even suggest that the Hanging Gardens were built by Senaherib, not by Nebuchadnezzar II (ca. 100 years earlier).

Description
Detailed descriptions of the Gardens come from ancient Greek sources, including the writings of Strabo and Philo of Byzantium. Here are some excerpts from their accounts:

"The Garden is quadrangular, and each side is four plethra long. It consists of arched vaults which are located on checkered cube-like foundations.. The ascent of the uppermost terrace-roofs is made by a stairway..."

"The Hanging Garden has plants cultivated above ground level, and the roots of the trees are embedded in an upper terrace rather than in the earth. The whole mass is supported on stone columns... Streams of water emerging from elevated sources flow down sloping channels... These waters irrigate the whole garden saturating the roots of plants and keeping the whole area moist. Hence the grass is permanently green and the leaves of trees grow firmly attached to supple branches... This is a work of art of royal luxury and its most striking feature is that the labor of cultivation is suspended above the heads of the spectators".

More recent archaeological excavations at the ancient city of Babylon in Iraq uncovered the foundation of the palace. Other findings include the Vaulted Building with thick walls and an irrigation well near the southern palace. A group of archaeologists surveyed the area of the southern palace and reconstructed the Vaulted Building as the Hanging Gardens. However, the Greek historian Strabo had stated that the gardens were situated by the River Euphrates. So others argue that the site is too far from the Euphrates to support the theory since the Vaulted Building is several hundreds of meters away. They reconstructed the site of the palace and located the Gardens in the area stretching from the River to the Palace. On the river banks, recently discovered massive walls 25 m thick may have been stepped to form terraces... the ones described in Greek references.