The next Olympic Games, held in Beijing, China, begin in exactly one years time, on 8 August 2008.
Starting today, there are 366 days to go until the opening ceremony.
Thousands of people across China were celebrating the start of the countdown.
A total of 999 children from across the country played music on the Great Wall of China.
They were playing traditional musical instruments on the wall, bits of which are around 2,000 years old.
The wall stretches for around 6,000km across the country.
As well as traditional instruments, there were displays by groups operating the dragons the country is famous for.
The organisation was amazing with all these people holding red fans.
And it's not really a celebration without fireworks, is it?
But a lot of people are getting worried about the air in China, which can get very smoggy, and make it difficult for athletes to breathe.