It was used as a reference to document that the Pharaoh was called by two different names. To get an idea of distances, here is a view of Cairo from Saqqara. Note that it gets greener by the Nile. Here are other pyramids at Saqqara, as well as the Giza pyramids, faintly seen on the left. To contrast the desert with the Nile area, here is a picture of a woman near an irrigation canal.
Water is life.