How hard is it to travel around London in a wheelchair?
There is less than a week until the London 2012 Paralympics begin with all sorts of sports like sitting volleyball and wheelchair basketball.
But what's life like if you're a child who needs a wheelchair to help you get around a big city like London?
Well, Newsround spent an afternoon with 11-year-old Calum as he travelled to the Olympic Park to find out about the difficulties he faces on public transport.
Find out how he got on.