Forget about Beverly Hills, 90210. America's most expensive zip code is actually 33109 — Fisher Island, just south of Miami, Florida. Fisher Island is so exclusive, you can only reach it by ferry or private boat.

The private island is home (in some cases, a second or third home) to some of America's elite. Oprah Winfrey and Mel Brooks reportedly own houses on the island, which is the site of numerous mansions, luxury apartment buildings and a hotel.

Expensive luxury apartment buildings on Fisher Island. Jeffrey Greenberg/UIG via Getty Images

The island was bought by Miami Beach founder Carl Fisher in 1919. The developer bought the island from Miami's first black millionaire, Dana A. Dorsey, and named it after himself, Forbes reports. Eventually, Carl Fisher traded the island for William K. Vanderbilt II's yacht, which he had long coveted.

The Fisher Island Club, an exclusive hotel on the island, restored the Vanderbilt Mansion and made it a focal point of the resort.

A search for available homes on Fisher Island reveals the most expensive home currently for sale costs more than $26 million.

Residents can enjoy a private marina and a golf course at the center of the island.