I photographed this snake high above my head amongst stonework in an arched entrance to an archeological site near Dalyan, Turkey in early May this year. The snake was showing unwanted interest in the nest of a a pair of Rock Nuthatch who eventually drove it way.
It Also looks like a Horseshoe Whip snake (Hemorrhois hippocrepis)
I'd be fairly confident with the turkish mountain viper especially given the terrain in the photo however Florin's suggestion is very possible too, for some reason i get a distorted view of your picture however if you remember the shape of its head that'll give you your answer, if it was very triangular it would be the viper, and if it had a fairly slim jaw not much wider than its neck then it's likely Florins
I'd go with situla. Horseshoe whipsnakes seem to be found only in Iberia according to Arnold and Burton-Collins book.