In the exclusive Bel Air neighborhood of Los Angeles sits a new monument to opulence, a $250 million mega-mansion that's now the most expensive home listed for sale in the US.

The four-level, 3,500-square-meter property comes with a seven-member staff, a $30 million car collection and an infinity pool complete with a swim-up bar, 270- degree views of the city and a 6-meter outdoor television.

It has 12 bedroom suites, 21 bathrooms, five bars, three gourmet kitchens, a spa, a 40-seat movie theater, and a bowling alley.

The mansion was built on speculation, or with no buyer in mind. And only 3,000 people in the world could afford to buy it, said Bruce Makowsky, the developer and owner of the home who made his fortune as a handbag designer.

"After being on major mega-yachts across the world and on beautiful private aircraft, it didn't make sense to me that people were spending $350 million on a boat, $100 million on a plane and they're living in $20 million and $30 million homes ... The homes have not kept up with the toys.

"So my feeling is if you're going to spend over 12 hours a day in your home it should be the most amazing experience in the world," he said.