Indian Creek Island, also known as “the Billionaire Bunker,” is a 300-acre, man-made strip of land in Biscayne Bay just north of Miami Beach that has attracted the ultrarich in droves. Its monied residents include NFL quarterback Tom Brady, Amazon founder Jeff Bezos, and President Donald Trump’s daughter Ivanka Trump.

The main island contains a mere 41 lots of purely waterfront property, adding another layer of exclusivity on top of the inflated cost to entry. The island’s interior is dominated by the Indian Creek Country Club and its private 18-hole golf course. Those looking to rub shoulders on the links have to reportedly pay a $500,000 initiation fee and go through a lengthy admissions process.

Though properties could be had for less, Meta CEO Mark Zuckerberg became the latest billionaire to reportedly snatch up a newly completed mansion at an estimated price tag of between $150 million and $200 million earlier this month. And of the ultrawealthy who can afford to shell out millions for a home, many often tear down the existing structure to build a new one, said Michael Martirena, cofounder of the Ivan and Mike Team at real estate brokerage Compass.

The price of exclusivity

With only 84 residents as of 2020, Indian Creek Island is one of the most exclusive enclaves in America, and a big reason why is the privacy and security that it affords its ultrawealthy residents.

Indian Creek is an independent municipality with its own government and a police force that patrols the island 24/7 not only by land but also by sea. A single guarded bridge connects it to the mainland, and any visitors must show their ID and may even undergo vehicle inspection, said Martirena, who has toured properties there with clients.

“It’s a bubble, and no one can get on and off, unless you have a reason,” said Martirena, who specializes in ultra-luxury real estate. 

Unlike nearby South Beach celebrity enclaves such as the Palm, Star, and Hibiscus Islands—where boat tours regularly pass by waterfront mansions—Indian Creek’s marine patrols keep onlookers away, Martirena told Fortune.

Because of the island’s location and strategic landscaping, very few homes in the surrounding areas, like the Bay Harbor Islands or Surfside, have a clear view of Indian Creek Island. This makes it very private, said Martirena, and very desirable. 

“It’s the place to be,” said Martirena. “People of that caliber feel safe and not bothered.”

And yet wealth alone doesn’t guarantee access. All the listings are done “off market,” said Martirena, meaning a buyer’s agent will have to deal directly with a property owner’s representatives, and contact them multiple times if they are not quite ready to sell.

“It’s a small community, and just to keep the chatter at a low level they do it all internally and very private,” he said.

In an already exclusive community, the western side offers an even more seclusive experience because the lots border the intracoastal waterway separating the island from the mainland, Mick Duchon, a Miami Beach–based real estate agent with the Corcoran Group, previously told Fortune. On this side of the island, home to two of the five richest people in the world, Zuckerberg and Bezos, the lots measure about 80,000 square feet, compared with 50,000 square feet which is the norm on the island, Duchon said.

Since announcing his move from Seattle to Florida in 2023, Bezos snapped up three properties on the island for more than $230 million combined. He’s turning two western lots into a compound while he lives in a Mediterranean-style house on the third lot on the other side of the island.

The billionaire migration to Indian Creek reflects a broader influx in South Florida luxury real estate, which Martirena described as “COVID 2.0.” Thanks in part to Florida’s lack of a state income tax, interest from high-end buyers is exploding even as activity at the lower end of the housing market slows. 

Another factor is the proposed 5% billionaire wealth tax, which is gathering steam in California. Google cofounder Larry Page has reportedly begun shifting assets, including his family office, out of California. The billionaire recently paid $173 million for two waterfront mansions in Miami’s Coconut Grove neighborhood. 

Martirena said his own business has picked up over the past couple of weeks, with three recent inquiries that he attributed directly to the potential wealth tax.

“They’re kind of preplanning ahead of time. They don’t want to move here,” he said. “They want to stay in the state of California, because they love where they’re at, and they never thought of moving. But they work very hard for their money, and they said they like their pocketbook much more.”