The owners of a custom-built mega mansion in Bel Air, California, are seeking $400 million for the property, which if sold at that price would make it the country's most expensive residential sale ever. The home, named "the Crown Jewel of Los Angeles," was completed around 2018 and boasts 70,000 square feet across multiple structures. The main home features 10 family bedrooms, 13 staff bedrooms, a 30,000-square-foot guest house, 39 bathrooms, and three swimming pools. The property is owned by an entity tied to Qatar's ruling Al-Thani family, which paid $35 million for a 7.8 acre site in 2010. It took about 10 years to complete at a cost of more than $350 million.