The Beijing Organizing Committee for the Games of the XXIX Olympiad announced on Tuesday that Beijing will hold a series of celebrations to mark the 100-day countdown to the Beijing Olympic Games. 10,000 runners will take part in a marathon on April 30 to the National Stadium, also known as the "Bird's Nest". The Olympic Park will not open to the public visitors during that period. Due to this reason, MDM organizers have to cancel our planed Olympic Venues tour on that afternoon.