There is considerable doubt in my mind whether this account of a journey to Petra should appear in a journal of ANTIQUITY’S standard of integrity. The only reason why I have agreed to allow it to be published is that I hope it will arouse interest in this neglected part of the late Roman Empire, with the result that some responsible archaeologist will follow in our footsteps and also see to it that some photographs are taken from the air. This is particularly important, because in the general dun yellow of the desert sand with its outcrops of umber brown rocks, it is extremely difficult when one is on the ground level to decide if one is looking at natural formations or the general lay-out of some vast irrigation system. I realized this the first time I flew from El Arish on the coast to Kosseima, and saw that this stretch of seemingly bare desert I knew so well was dotted thickly with the remains of small stone farm-houses and orchards, and that there was a general scheme of irrigation in every wadi (dry water-course).