High above Los Angeles, in the hills of Bel Air, a clash of the titans is playing out.
Two rival "mega mansions" are on the market, both vying to become the most expensive house ever sold in the United States. What is more, they are both right next door to each other.
On one plot stands a US$188 million home named simply "Billionaire", the Daily Telegraph reports.
Currently owned by luxury handbag entrepreneur Bruce Makowsky, the estate at 924 Bel Air Road boasts 17 bedrooms and 21 bathrooms, linked over four floors, by lifts lined with crocodile skin.
With an infinity pool overlooking LA and a series of grassy terraces, spread over 3900sq m of indoor and outdoor space, the property features floor-to-ceiling windows and glittering chandeliers.
An enormous garage sits under the pool – filled, in the estate agents' pictures, with glistening black sports cars. A helicopter is handily parked on one of the lawns, just outside the home office window. Water flows around the house in sleek channels, illuminated at night.
The estate boasts five bars, a massage studio and wellness spa, fitness centre, and 40-seater home cinema.
The owner can also entertain guests at a four-lane bowling alley, or at the outdoor pop-up cinema – while serving drinks from the two cellars and three kitchens, and listening to music from what the agent describes as "the most advanced home tech system in the world."
Makowsky's property is said by Branden Williams, selling the property for Hilton Hyland, to be an "indoor/outdoor nirvana enhanced by 270-degree unobstructed views spanning from the mountains all the way to the ocean, and the incredible Los Angeles skyline in-between."
But it has competition.
Next door sits a similar property, on the market for US$180 million – also being marketed by Williams.
The second home has been developed by Dr Raj Kanodia, a prominent Los Angeles plastic surgeon whose clients include Britney Spears and Kim Kardashian West.
Kanodia bought the space in 2011 for US$6.8 million, and said he has spent roughly US$45 million on developing the property.
Roughly 3160sq m, the nine-bedroom mansion has a Portuguese limestone facade, a double-height entry and a floating staircase.
There are wall-to-wall glass doors, two kitchens and a 2000-bottle wine room - encased in white oak and glass. The house has a gym designed by celebrity trainer Harley Pasternak, and outdoors, on 0.4ha, is the waterfall, a vegetable and herb garden and an outdoor kitchen with a grill and pizza oven.
Kanodia smiled at the initial scepticism from real estate veterans.
"They said 'What the hell is he doing playing in the big leagues?'" he told the Wall Street Journal.
"Like they say in poker, I'm all in - times millions. Being a surgeon, I take very calculated risk."
He and Makowsky – who originally listed Billionaire for US$250 million last year, lowering the price in April – also laughed off the rivalry.
"We communicated, chatted and collaborated many times," said Dr Kanodia. "He was laughing at me, saying I'm in the wrong business."
Makowsky said there might be friendly competition, but said he wishes Kanodia the best.
"I hope he gets his price, and I get mine," he told the paper.
The current record for America's most expensive home is ever sold is a sprawling estate in the Hamptons that sold for US$137 million, in 2014, to hedge fund manager Barry Rosenstein.
