The Hanging Gardens of Babylon are thought to have been built in the ancient city of Babylon. Even though there is no proof that they actually existed, they are considered to be one of the Seven Wonders of the Ancient World. It is called the Hanging Gardens because the gardens were built high above the ground on multi-level stone terraces. The plants weren't rooted in the earth like a traditional garden. If it existed it was likely the most beautiful man-made gardens ever created. It is the only wonder of the list that we are not sure really existed, despite the fact that lots of Greek writers wrote about them and how they were built. The most popular theory is that the gardens were built by the king of the neo-Babylonian empire Nebuchadnezzar II to make his wife happy. She was homesick for the plants and gardens of her homeland. The innovative structure and the advanced water irrigation system utilized by the Babylonians made the Hanging Gardens earn a spot in the List. Nowadays they would be by the city of Bagdad, Iraq.