The picture above comes from Santorini, and is one of the most famous scenes in all of Greece. The turquoise-topped churches and the whitewashed houses are striking, and you shouldn't miss your chance to take pictures and take time in such places.
But take care not to shortchange yourself by only checking off a few famous spots like this one and perhaps the Acropolis in Athens. Add value to your trip by visiting lesser-known islands where you can observe the quiet everyday existence of Greeks without having to move so another tourist can take your place for a photo opportunity.
