The secret affordable coastline that in-the-know Floridians love
 
        
    Just north of Palm Beach is the laid-back, outdoorsy Martin County, a slice of the Sunshine State without the crowds Only 30 minutes’ drive from the mansions and skyscrapers of Palm Beach County — home, at last count, to 58 billionaires and one sitting president — is a quiet stretch of sand lined with wild…
 
                 
         
         
        