The last piece of turf has been laid at the Olympic Stadium, symbolising the completion of building work on the 80 thousand-seat flagship venue for the 2012 London Games.
Former Olympic sprinter Frank Fredericks used a shovel to lay down the symbolic last piece of grass on the infield, 16 months before next year's games.
London organisers and International Olympic Committee officials visited the stadium to mark the milestone.
Fredericks was among the members of the IOC coordination commission taking part in the ceremony at the Olympic Park in east London. The IOC panel is making its eighth visit to London to check on preparations for the games.
Construction on the 1 billion dollar stadium began in May 2008.
The stadium will host the Olympic track and field competition and the opening and closing ceremonies in 2012.
After the games, the stadium will be converted to a 60 thousand-seat venue that will serve as home to West Ham football club.
The arena will also host athletics competitions, concerts and community events.