Madain Saleh (مدائن صالح , also Medain Saleh) is a large archaeological site in Saudi Arabia.
A Nabataean city hewed out of rock in the same style as Jordan's far more famous Petra, Madain Saleh is on UNESCO's tentative list for World Heritage inclusion  and would be a top tourist draw in any other country than Saudi Arabia. As it is, though, access to the site is fairly difficult and many Muslims refuse to enter the area because it was narrated in Bukhari  that when the Prophet Muhammad passed by this area, he told his Companions, "Do not enter the dwelling places of those who wronged themselves, lest there befall you what befell them, unless you are weeping." There is also a section in the Qur'an (Al-Hijr 15:80) that explains the story of these houses.
A permit is necessary for visiting Madain Saleh (however some tourists claim that they were allowed in based on their ID only). Tour operators or hotels will usually arrange these on your behalf but you need to apply at least one week in advance. You can do it yourself at the Saudi Commission Of Tourism and Antiquities (SCTA) localized in the Diplomatic Quarters..
TIP: If you have your reservation with Al Ula ARAC Resort you shall call Mr. Ahmed Salah 0568565391 and he will arrange the permit for you free of charge.
There are two weekly flights to AlUla airport operated by Saudi Airlines now. The airport is located around 15km South East from AlUla town.
Other airports are in Al Wajh (220 km) and Medina (300 km, and yes, the airport is open to non-Muslims). Until 2004, visitors usually traveled via Hail (400 km), but a new road from Al Wajh now makes that route considerably faster.
Facilities all set up and ready for tourists (as of 2000 anyway), but LOCKED tight as a drum! Travel around inside as much as possible, there are many little interesting things to see. Use of steel sleepers stolen from the railway for all sorts of agricultural uses, and so on.
During your visit to Madain Saleh Area , you can eat good food in your hotel , (ARAC Al-Ula Hotel 4+ stars or Madain Saleh Hotel also 4 stars category), both hotels offer good and clean food , also if you want to try the local food you can visit to nice and clean resturants in the city of Al-Ula. your tour guide should guide you to the best places to eat.
Staying overnight at Madain Saleh is not allowed, so most visitors use one of the two hotels in Al-Ula.
You can, if so equipped, camp quite close to the gates of Medain Saleh quite readily. There are organised tours which set up outdoor camps in a very luxurious fashion near the entrance.