A film producer is building one of the largest mansions in US history — and he wants to sell it for $500 million

Will Smith may be the "Prince of Bel-Air," but Nile Niami is the king.

The film producer and residential developer is building one of the largest homes in US history on a hilltop in Southern California.

Set to be priced at $500 million, it will be the most expensive home on the international real estate market.

The kingdom won't be completed for another 20 months, so start saving. 

McClean Design, which specializes in contemporary architecture, is masterminding the 100,000-square-foot compound. "The house will be using artificial turf and zero water will be used for the lawn," a representative from the firm told Business Insider.

In addition to the 74,000-square-foot main residence, there will be three smaller homes on the property, plus ample staff quarters. The master suite will pack twin walk-in closets, bathrooms (plural), a sitting room and office area, and an infinity pool.

Now for the fun part: amenities. How do a 30-car garage, tennis court, gym/spa, four pools, and a "jellyfish room" sound? The latter will feature tanks on the walls and a sea-creature light show on the ceiling.