Looks like one of the buildings in the Acropolis, the Temple of Erectheion.
https://www.airpano.com/gallery.php?gallery=19&photo=746
https://goo.gl/maps/qXxyPAMKPu12
Our fathers and grandfathers visited so many amazing places, but in the name of defending our way of life, rather than as tourists. We never thought to ask them about the places, for many were understandably reluctant to talk about the war itself. Maybe we should have asked them that, it may have helped open up things that needed opening up, or maybe not.
One of my grandfathers was in the First World War, I think attached to communications or similar. He served as an Air Warden in the second. The other was in North Africa in WWII, a tank driver captured in one of the hellish battles there, and MIA for several years before my grandma got a postcard from an Italian POW camp, a card we found after she died and the single most moving piece of literature I have ever seen. He must have seen some places, but died before I was old enough to talk to him about them.