Location: Olympic Park in London's Stratford district. With the BMX racing track, it completes the London Velopark.

Events: Track Cycling

Construction: Built between 2009 and 2011, at a cost of approximately $164 million

Nails Used: 350,000

One of the most iconic venues of the 2012 Summer Olympics is also one of the most sustainable. The Velodrome roof, which resembles the track it contains, is strung like a tennis racket, with a cable-net design, reducing the amount of materials (and time) needed to complete the project. The design of the roof also allows for natural ventilation and natural light, reducing the needs for air conditioner and artificial lighting, respectively. But perhaps most impressive is that the roof collects rain water, reducing the amount of water used from the municipal system by as much as 70 percent.

Photo by Paul Gilham/Getty Images

The Velodrome track, which will be the site of all the high-speed track Cycling events, from Team Sprint to Keirin, has already been praised as the world's best by many cyclists.

Rob Webb, designer of the velodrome tracks at both the Sydney and Athens Games, was charged with the same duties for London, where he collaborated with a panel to create the fastest track possible. The 250-meter track was built with some 56km of Siberian pine, yet another sustainable decision.

After the Games, the Velodrome, as well as the whole Velopark, will be turned over too the Lee Valley Regional Park Authority and will continue to be used by local clubs and elite athletes.