The list of architectural marvels continues to grow with news from Dubai that Emaar Properties is set to construct a radical new skyscraper, topping the Burj Khalifa's claim to the title of the world's tallest building.
But what if the building, as of yet to be named, doesn't make it off the drawing board?
The history of architecture is littered with failed ventures -- scuppered on the rocks of hubris, bad luck and financial meltdowns. Line these projects up and it makes for fascinating reading.
There's a parallel world out there waiting to be explored: an alternative history where skyscrapers are already a mile high, Russia had a skyscraper to trump the Empire State and Gaudi left his mark on downtown New York.
It's a pipe dream, yes, but for fans of architecture it's one worth indulging.
Scroll through the gallery above to discover the greatest buildings that never were.