I have finally found the official permit for the archaelogical sights in Athens. According to the official decree they asked to make shoots at Acropolis, the Handrian Library, the Monument of Lysicrates, the Temple of Olympian Zeus and AreiosPagos (pit stop). Keep in mind that they didn't necessarily visit all of the above as the permit included also aerial shots. I couldn't find anything similar for the archaelogical site of Delphi so they might not have visited it.