America’s most expensive home sells for $238m to hedge fund boss

Penthouse at 220 Central Park South is 34 times bigger than average Manhattan apartment: ‘Hope he got a lot of bathrooms,’ says homelessness advocate

Ready for liftoff? Two flying taxi startups got Pentagon funding

Exclusive: Self-flying vehicle firms got $2m last year, as US military envisions taxis as more Blade Runner than Back to the Future

Welcome to Powder Mountain – a utopian club for the millennial elite

When these young entrepreneurs bought a remote ski resort in Utah, they dreamed of an exclusive, socially conscious community. Is this the future, or Mt Olympus for Generation Me?

America’s costliest house: developer takes $500m gamble on Bel Air eyrie

Niles Niami specialises in homes for the super-rich. All he needs is a billionaire to snap up his LA hilltop mansion called The One

Revealed: Sergey Brin’s secret plans to build the world’s biggest aircraft

Google co-founder is building airship designed to be able to deliver supplies and food on humanitarian missions to remote locations, sources said