The last of the classical sources thought to be independent of the others is A Handbook to the Seven Wonders of the World by the paradoxographer Philo of Byzantium, writing in the 4th to 5th century AD.[18] The method of raising water by screw matches that described by Strabo.[19] Philo praises the engineering and ingenuity of building vast areas of deep soil, which had a tremendous mass, so far above the natural grade of the surrounding land, as well as the irrigation techniques.

Historical existence
This copy of a bas relief from the North Palace of Ashurbanipal (669–631 BC) at Nineveh shows a luxurious garden watered by an aqueduct.
It is unclear whether the Hanging Gardens were an actual construction or a poetic creation, owing to the lack of documentation in contemporaneous Babylonian sources. There is also no mention of Nebuchadnezzar's wife Amyitis (or any other wives), although a political marriage to a Median or Persian would not have been unusual.[20] Many records exist of Nebuchadnezzar's works, yet his long and complete inscriptions do not mention any garden.