Hegra, also known as Mada’in Salih, is an archaeological site located in the area of al-'Ula within Medina Province in the Hejaz, Saudi Arabia. A majority of the remains date from the Nabataean Kingdom. The site constitutes the kingdom's southernmost settlement and its second largest city after Petra, its capital city. Traces of Lihyanite and Roman occupation before and after the Nabatean rule, respectively, can also be found.
The Quran places the settlement of the area by the Thamudi people during the days of Salih, between those of Nuh and Hud on one hand, and those of Ibrahim and Musa on the other. However, a definitive historical chronology can not be obtained through the order of verses due to the fact that the Quranic chapters deal with different subjects in non-chronologic order.
Wikipedia https://en.wikipedia.org/wiki/Qasr_al-Farid
Address Saudi Arabia
Coordinates 26°46'26.325" N 37°57'40.384" E