The fabric of ancient civilization
Venice is populated entirely by pedestrians and boats ... there are no highways, no skyscrapers, no crosswalks, no streets. And yet, this is a city structure of high civilization.
It has been like this, without break, since before "Rome" fell. Of course, Rome wasn't the Roman empire, when it was sacked in the 5th century. The Roman Empire since the 4th century was what we would call Byzantium, with HQ in Constatinople. Venice gets much of its civilization, its current civilization, from this Roman Empire. And, in fact, Venice famously sacked Constantine's city in its dotage. The Turks finally terminated the Roman Empire in 1453, when much of Constantinople's power, population and influence had already moved to Venice.
What we see, in Venice, is the living fabric of an ancient city. In their monumental architecture, what we call "renaissance neo-classical" is actually classical, because this is what they inherited. In the 14th century, Roman churches were still operational (some are today), and though fashions changed, they changed also in ancient times, with about the same latitude. Add to this the living, working structure of the city in Venice, used today in approximantely the same way as it always was. Accent this with the flair and exhuberance of a madly successful and powerful ancient city, and you get Venice. It's not unchanged -- and there are small modern reminders everywhere. But if you look around, you don't even need to squint to imagine that you're part of an unbroken chain of high civic achievment going back at least to golden age Athens.