Galeries Lafayette heir joins French tycoons in opening art foundation

Guillaume Houzé’s cultural centre will rival that of France’s richest man, Bernard Arnault

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

A whirl through Vienna’s modernist era, 100 years on

Celebrating a century at the heart of the modernist movement, the Austrian capital is putting on quite a show

Not the end of The World: the return of Dubai’s ultimate folly

Underwater bedrooms, ‘Lohan Island’ and snow all year round – a decade after it was scuppered by the financial crash, the fantasy archipelago of 300 artificial ‘countries’ is back in business. Has anybody learned anything?

The £3bn rebirth of King’s Cross: dictator chic and pie-in-the-sky penthouses

Google HQ, boutique shops in old coal sheds, gasholders offering wedge-shaped flats at sky-high prices … as the vast project comes together after 18 years, our critic gives his verdict