According to friends of mine who live there, the secret's gotten out and the housing prices have correspondingly skyrocketed. I believe something similar has happened in Portland.

As far as I can tell, the best "cool place that nobody knows about" must be Salt Lake City. So many (non-Mormon) people are turned off by the Mormon-centric nature of the place that they miss what a great place it is. I had a job offer, way back when, from the U. of Utah, so I gave a lot of thought to the place... and ended up in Houston instead. Sigh.