The athletics track at London's Olympic Stadium, which will host next year's games, was inaugurated on Monday.
The red synthetic rubber track, made by an Italian firm, was tested by several athletes including middle-distance runner Hannah England, who won a 1500m silver medal at the recent world championships.
"It's a great moment," said organising committee president Sebastian Coe, himself a former elite middle-distance runner.
"The Olympic Stadium is starting to take shape and people now have a glimpse of how it will look in less than 10 months."
The 80,000-capacity stadium, situated in London's East End, is expected to have cost Â£486 million ($753m) to build when completed.
It will host the opening and closing ceremonies at the 2012 Games, on July 27 and August 12.