File photo taken in 2007 shows the mountains in the archaeological site of Al-Hijr, also known as Madain Saleh, in Saudi Arabia. The highest volume of visitors is between December and March, given the... more 

File photo taken in 2007 shows the mountains in the archaeological site of Al-Hijr, also known as Madain Saleh, in Saudi Arabia. The highest volume of visitors is between December and March, given the lower temperatures in the otherwise scorching desert heat less