If I took any design lessons away from my visit, I would say the French from the 1600's through the early 20th Century were masters of drama and scale. 

For example, the central part of the city, as redesigned by Napoloeon, has massive, massive streets - huge concourses that stretch for a mile or more and end in a monument (such as the Arc de Triomphe, third photo down).   The reasoning behind Napoleon's design decisions (and the French royalty before him) was to increase the average person's sense of smallness and awe at the grandeur around them.  It is exhausting to walk along one of those giant streets, the scale is superhuman and it plays tricks on your perceptions of how far away things really are. 

Another example that I saw everywhere were enormous staircases, enormous sculptures, and enormous urns.  You can't swing a dead cat in Paris without hitting an enormous urn!  :)

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