The word "Khazneh" Treasure, was given by the local Bedouin tribes behind the belief that the urn on top of the front entrance contained the treasure of a pharaoh. Know More
Can you go inside the Treasury at Petra?
You can't go inside the Treasury at Petra. Entering the Treasury was allowed but the government stopped it as it was concerned about its preservation. However, the Treasury from inside is empty, as when the Nabataeans carved Petra, they were very focused on the facade.