Yuri Milner's $100million French-chateau-style mansion sits in Silicon Valley, where the investor in Facebook, Zynga, Twitter, Spotify, ZocDoc and Groupon rests his head.

The Russian investor purchased the extravagant estate in March 2011, when it was one of the most expensive real estate sales in the entire country.

The home, which was reportedly not even on the market when he bought it, is now valued to be worth only $50million.

The 30,000sqft home has five bedrooms, nine bathrooms, a ballroom, wine cellar and home theater.

2) BILL GATES, MICROSOFT

Bill Gates' Xanadu 2.0 is worth an estimated $121million. The Microsoft founder's 66,000sqft mansion in Medina, Washington, has incredible high-tech features like a pool with an underwater music system, a library with a domed reading room and heated floors and driveways.
Guests visiting the digitally-enhanced home must reportedly wear computerized pins so the house can monitor one's travels throughout the many halls and rooms in order to adjust the music, lighting and climate settings to the person's preference.
Xanadu 2.0 took seven years to build and cost $63million.

1) LARRY ELLISON, ORACLE

Larry Ellison's personal island of Lanai takes the cake for most expensive 'home' at a cool $600million.
The cofounder and CEO of Oracle purchased 98 per cent of the island in June 2012, allowing him to call the 141sqmiles of pristine nature his own.
Mr Ellison's plans for the island are not yet known.