If you are interested in art, then Athens should be the place to go to next. The art scene in Athens is booming. New cultural spaces open almost daily. Studios and apartments are turned into galleries. For artists, living in Athens is cheaper than elsewhere. Artist have moved their studios from London and Berlin to Athens. And art is seen in Athens, not only bought.
The Acropolis has become the byword for Athens, though every Greek city sported an acropolis, an upper town. It was built and destroyed several times during its 7,500 years of history and it found many uses. What sticks in the mind, though, is the moment when the Venetians blew it up.