The world's tallest building has just got taller.

The Burj Dubai, which means Dubai Tower, is still being built but has so far reached 688 metres making it the greatest man made structure of all time.

The 160 storey skyscraper - which is already the equivalent height of about 53 giraffes - dwarfs the world's other tallest buildings the CN Tower in Toronto and Taiwan's Taipei 101.

Five thousand people continue to work on the tower which is expected to be finished within the next year.

The developers, Emaar, will not say what the final height of the structure will be but there is speculation it could be as tall as 900 metres.

When it is finished, Burj Dubai will be able to hold 35,000 in hotels, apartments and offices.

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