Tour a little-known island off the coast of Miami that once belonged to the Vanderbilts and is now the most millionaire-dense ZIP code in America

Fisher Island, Florida, is a paragon of exclusivity.

The 216-acre, man-made island sitting pretty off the coast of Miami Beach is reachable only by boat - most often yacht. It's considered America's most millionaire-dense ZIP code, but less than 20% of the island's residents permanently reside there.

With its mix of condos, private homes, and hotel rooms, the lush island exists as a retreat for the ultra wealthy, who spend their days golfing, playing tennis, lounging on the beach, boating, and simply relaxing.

The illustrious Vanderbilt family were the original stewards of Fisher Island, and their penchant for opulence remains.

Below, find out how Fisher Island became one of America's most affluent enclaves.