Did some digging Pluss.
Found out some pretty interesting stuff.
That photo, by the Phrase and the Architecture, and by looking at the 45th's service record. Was probably taken during Operation Dragoon, The invasion of the Southern Coast of France (ordered by Churchill) after the Italian Campaign.
If its not there its definitely Italy somewhere. Its Christian definitely, possibly near a building of official function like a Church or Monastic Library or maybe Town Hall.
My guess would be one of three places.
Comiso in Sicily, Salerno in Italy, Or Grenoble in Southern France. Or at least towns and counties in the area of those places. The Tiered Construction of the building behind him suggests French though. But Im not an expert.
Start looking near or around one of those places.
Hope I Helped, probably didn't though