2012 Olympics: London Mayor Boris Johnson on 'huge challenges'
27 July 2011 Last updated at 15:55 BST
Events are being held in London to mark the start of the 2012 Olympic Games in one year's time.
London Mayor Boris Johnson has taken a tour of The Aquatics Centre in the Olympic Park, London.
There are "huge challenges" ahead but the right team is in place to deal with them, he said.