Upon the order of Beijing Urban Construction Group Chairman Liu Longhua, the last piece of concrete was placed onto top of the National Stadium, completing the main rooftop structure. Also known as the "Bird's Nest," the main part of the facility's roof has been completed ahead of schedule.

As the venue for the 2008 Beijing Olympic Games opening and closing ceremonies, as well as the track and field events' main competition site, the "Bird's Nest" is the most difficult and high-tech construction project among Olympic facilities.

With a height of 68.21 meters, the elliptical, saddle-shaped building covers an area of 258,000 square meters. The structure is composed of an underground level and seven floors above ground, with room for 91,000 spectators.

It took 42,000 tons of steel to concretize the "Bird's Nest" design. Currently, the National Stadium holds the international record for the facility composed of the largest quantity of steel. Using the world's top construction and engineering technology, the stadium is designed to last 100 years.

The Beijing Urban Construction Group noted that after the roof of the "Bird's Nest" had been placed, the construction will enter a secondary stage that will also be the most difficult. The entire steel structure is planned for completion in November of next year.

"Bird's Nest" Milestones

December 24, 2003: Construction begins on the "Bird's Nest

July 27, 2004: Wang Qishan, Mayor of Beijing, declares that the Beijing BOCOG and other relevant departments must firmly establish the concept of a cost-friendly Olympics, making great efforts to reduce project costs

July 31, 2004: Municipal Government and BOCOG announce "Bird's Nest" construction temporarily suspended, pending adjustments

August 6, 2004: "Bird's Nest" adjustments are contemplated, mainly involving open-style roofs and wider openings

December 28, 2004: Resumption of construction of "Bird's Nest"

November 15, 2005: "Bird's Nest" main roof construction sealed ahead of schedule