In the desert landscape of northeastern Saudia Arabia you will find Qasr al-Farid aka “The Lonely Castle”. Built in the first century A.D. the Lonely Castle rises four stories; an unfinished tomb carved out of a solitary sandstone outcrop. Because the tomb was never completed, we can see how the façade was chiseled from the top, down.
Qasr al-Farid is part of Mada’in Saleh, a pre-Islamic archaeological site located in Al-Ula, Saudia Arabia. A majority of the vestiges, including 131 rock-cut tombs, date from the Nabatean Kingdom (1st century AD). The site constitutes the Nabatean Kingdom’s southernmost and largest settlement after Petra, its capital, located in present day Jordan.
In 2008 UNESCO proclaimed Mada’in Saleh as a site of patrimony, becoming Saudi Arabia’s first World Heritage Site. [source]