while traversing the Bab al Siq, which is the 600 meter flat walk before the entrance to the Siq, you will see assorted geometric blocks scattered around the area and these are calle the Djinn Blocks, which are actually dedicated to the Pre Islamic Arabian Gods and also are the locations of tombs for Nabateans nearby. The Djinn Blocks are actually tombs and are believed to be the earliest tombs in Petra. About 26 different Djinn Blocks were found throughout the park. The block shape may represent the ancient Nabataean god Dushara and other Nabatean Deities.
On the road into Petra, you can see some of the earliest examples of their work. The Djinn Blocks are representations of the Nabataeans gods (Djinn meaning spirit). The first two are on your right about midway along the road, near a small set of cave dwellings, and there's another just after the bridge before the Siq.
These are the first sign that you are approaching something special. They are huge blocks of stone, lightly carved, on the right hand side as you go down the road to Petra. They are also called "god blocks"
Their exact purpose is unknown, they seem to be associated with water, there are a number of them scattered around the outskirts of Petra, usually close to a water course.
The word Djinn in Arabic mean "spirit" because the tradition want that these blocks were use to accomodate the spirits.
Nobody know nowday which is the use of these blocks but they are very fascinating and they are the first meeting that visitors have got in their exploration of the Pink Town.