But a new mega-mansion is soon to hit the market with a price tag only the super rich can afford: $500 million. When it goes on sale, it will become the most expensive house in the United States, eclipsing the Chartwell estate, known as the setting of "The Beverly Hillbillies" and currently on the market for $350 million.
Dubbed "The One," the 100,000-square-foot estate, located in Los Angeles' Bel-Air neighborhood, was designed by luxury real estate developer Nile Niami, who set out to build the most extravagant home in the U.S.
Construction on the house began in 2013 and is expected to finish next year. However, Niami gave CNBC's "Secret Lives of the Super Rich" exclusive access to the building site.
The opulent structure sits high above L.A. on four acres of land, offering incomparable views of the city's skyline. "In one eye-line, you have from downtown L.A. to the ocean to The Getty [museum]," Niami tells Robert Frank of "Secret Lives."
Take a look inside, via computer-generated renderings of what the finished product will look like.
The building will only feature the highest-quality materials, including a mountain's worth of marble.
Once completed, "The One" will also go above and beyond the classic amenities of a mega-mansion. Residents can curl up with a book in the glass-encased library or perfect their bowling game at the home's private four-lane alley.
Netflix binges will be taken to the next level in the 40-seat movie theater.
The house even hosts its own nightlife with an indoor/outdoor nightclub on the premises.
One of the estate's most distinguishing features will be the jellyfish room, where tanks of jellyfish replace the walls, illuminated by black lights.
Outside, four infinity pools will cover the grounds and a moat will circle the entire property. "It will feel like the house is floating on water," Niami says.
When the mansion is completed, he's confident the right buyer will scoop it up. "There's a lot of people out there with a lot of money — they want something no one else can have," Niami says. "This is it."
"Secret Lives of the Super Rich" returns Thursday, Sept. 28 at 10PM.
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