Trafalgar Square has been transformed into a giant Boccia court to mark the start of the two-year countdown to the Paralympic Games.
Britain's Boccia team, the current Paralympic champions, took to the temporary court in London to show how the bowls-style game was played.
The 10,000-capacity landmark will be at the heart of celebrations for the Paralympics which start on 29 August.
It is also an official big-screen venue for the 2012 Games.
Paralympic Boccia champion David Smith, 21, of Eastleigh, Hampshire, who has cerebral palsy, said 2012 could provide "a new lease of life for the sport and get people to appreciate it".
He said: "Boccia is an easy game to play but I have to remind people that my co-ordination is shoddy. I have constant spasms and we do not normally play in a cross wind like today.
"Despite all of that I am as successful in my sport as Andy Murray is in tennis and I love it."
Watching the tactical team sport, London Mayor Boris Johnson said the whole of London would "celebrate like never before when the Paralympics come to town in 2012".
He said: "I am adamant that as many people as possible experience the feelings of exhilaration and national pride that the Paralympic Games create.
"With just two years to go the message from London to visitors and Paralympic athletes is loud and clear - let the celebrations commence as the Paralympics truly come home."