Tour the richest zip code in America — the mysterious members-only island in Florida where millionaires pay $250,000 just to participate

Fisher Island, Florida, is as exclusive as it gets.

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.

According to 2015 IRS data analyzed by Bloomberg, Fisher Island residents have an average annual salary of $668,900.

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

Below, find out how Fisher Island became America's most affluent enclave.

SEE ALSO: How many years it took the 23 richest people in the world to go from millionaire to billionaire

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