When the shortlist was announced, just before the Games began in July, judges described the Olympic Stadium in Stratford as having "a spirit of fun".
They said the architects had "designed a space to create an amazing atmosphere, where every seat has a great view".
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Transport for London is not happy that its branding has been used.
If you've been anywhere near Trafalgar Square today you'll notice something different.
Look closely at this collection of images by photographer Jim Grover and you'll notice there's something missing.