You know what, what a coincidence but I was thinking the same thing over the last week. Most big cities have nicknames like
Chicago/The Windy City,
New Orleans/The Crescent City,
Las Vegas/Sin City, and
New York/The City That Never Goes To Sleep. This may sound stupid or cool. How about The Art Capital of The South, or San Antonio: The Birth of Unique.
However, I DO LIKE The Big Mystery
Oh, before I forget, how about
The Only Major City Without a Tall or Supertall Skyscraper, tee hee!