The Treasury, with its beautiful sandstone facade, is undoubtedly the most important monument in Petra, and certainly one of the most popular tourist attractions in the world, a 39-meter-high mausoleum of the Nabatean king Aretas III, carved deep into the sandstone. Al-Hamra, and it dates back to the first century BC, and the treasury derives its name from the story that an Egyptian pharaoh stashed his treasure here while he was hunting the Children of Israel.