Most of the photos I own that were taken in Greece depict soldiers at the Acropolis in Athens. In that respect German soldiers didn’t differ from tourists since the 18th century, but I suspect that there could’ve been a deeper affinity for the ancient world. Hitler saw the Greater Germany as a successor to the empires of old, and classical architecture was an inspiration for monumental buildings designed by architects like Albert Speer.
This photo was taken in June 1943, a month after the German troops in North Africa on the other side of the Mediterranean had surrendered. The soldiers stand in front of the Propylaea, the monumental gateway to the Acropolis, erected over 2,300 years earlier. They wear the regular field uniform and not the tropical lightweight uniform one would expect. One of them wears the Infantry Assault Badge, while another wears the Wound Badge in black, which marks them as having some combat experience. Almost all of them are NCOs.
They do look tanned, though, and are probably not there on leave, as any leave would usually be spent back home. There were several units belonging to the German garrison in Athens, like the Alarm-Regiment Athen. It’s also possible that they belong to a unit that is stationed nearby, and that they have a short leave for a visit to Athens. Either way, they do look happy, even if Hitler’s empire wasn’t to last for more than two more years.