Nowadays, a summer vacation in Greece won’t surprise anybody, but winter is quite a different story. If you consider yourself adventurous, follow my advice: go to Athens for winter holidays.
The ancient Parthenon on the Acropolis mount (the Athenian Acropolis) floats above the city. There are few cities in the whole world able to compete with the capital of Greece for its notoriety and fame.
I have never regretted the trip to Athens for the Christmas holidays. The story of this city goes deep to ancient times, and the lack of historical data is fully compensated by an amazingly imaginative Greek mythology.