It's great traveling in Greece during the shoulder season -- the days are lovely and warm (not hot) and the crowds are few. I'm here in historic, bustling Athens, home of the world's top ancient site: the Acropolis. Athens, like Rome, went from being a major city in ancient times to nearly a ghost town, and then (partly because of its classical heritage) grew into a major city again with a population of several million.
As a tour guide, it's hard to describe Athens at the dawn of the modern age. This 19th-century Romantic etching does it well. Back then, the city was little more than a small town (today's Plaka) built around its ancient ruins.
In the city of Athens, even with its booming tourist trade, must-see sights, and cruise-ship crowds, there is only one sight where lines are a concern -- and that's the Acropolis. The good news: The Acropolis ticket is a combo-ticket that you can pick up at a number of other sights in town. Buy the ticket elsewhere and then use it to walk straight into the Acropolis. The cruise-ship groups get there first thing, but when I arrived around noon, the cruise-crowd rush hour was heading in the opposite direction.
The Acropolis experience is complete with a visit to the amazing Acropolis Museum. It basically takes all the surviving bits of carved marble (that didn't end up in London) and sorts them out in a setting that is the size of the Parthenon. You look out the window and see the remains of the actual temple above and then, with great comfort, lighting, and information, you enjoy the art -- quasi in situ.
Our challenge as travelers is to actually talk with the art.