One Canada Square

In 1991, One Canada Square, the UK's tallest skyscraper, changed the London skyline. But the Cesar Pelli designed icon wasn't in the heart of the capital.
Instead, the developers had taken a billion dollar gamble on creating an international financial centre, symbolised by this obelisk-shaped tower, in the desolate docklands of the city's East End.
But when the world property market collapsed just after the complex was completed, the developers went bankrupt and a large part of the tower lay in darkness...