The document discusses the Hanging Gardens of Babylon, one of the Seven Wonders of the Ancient World. It describes how the gardens were built by King Nebuchadnezzar II around 600 BC to please his homesick wife from the green mountains. An elaborate irrigation system lifted water from the Euphrates River to irrigate the multi-level gardens built on a large stone structure. While the gardens' existence has been questioned, they would have been a marvel of engineering to transport water to plants stacked several stories high in the flat Mesopotamian climate, if they did exist as described.