The countdown to the start of the London 2012 Olympic will reach a significant milestone on Wednesday as the countdown clock will hit 100 days.

Venue construction is all but complete with just temporary structures and final testing to come as London readies itself for the "greatest show on earth". The 2012 Games will use a mixture of newly built venues, existing facilities and temporary facilities.

The 2012 London Olympics will start in the Olympic Stadium in the south of the Olympic Park, home to athletics and the opening and closing ceremonies. The Stadium is the most sustainable ever built and will have a capacity of 80,000 during the Games.

Next is the Aquatics Center, the venue for swimming, synchronized swimming and diving. It has a 50-meter swimming pool, a 25-meter diving pool for the athletes.

The countdown to the start of the London 2012 Olympic will reach a significant milestone on Wednesday as the countdown clock will hit 100 days.

Over to the north of the Olympic Park, we will find the Velodrome, the venue for track cycling. The Velodrome's roof is designed to reflect the geometry of cycling...as well as being lightweight and efficient, like a bicycle. The 6,000 seat venue will be packed by hometown fans cheering on a strong Great Britain team during the Games.

From the Olympic Park to the Greenwich peninsula, which was originally built for Millennium celebrations, North Greenwich Arena has been transformed into a sports venue for the summer. It will host Artistic Gymnastics, Trampoline and Basketball finals during the Games.

Police officers keeps watch in Westminster near the London 2012 beach volleyball venue, in London, Wednesday, March 28, 2012.

Another transformed venue is ExCel, an exhibition and conference center in London's Docklands. It will host a range of sports during the Games, like table tennis, weightlifting, fencing, and boxing, as female competition will be on for the first time for Olympics.

And of course, what would a London Olympics be without the cities historic venues. The All-England club, the site of Wimbledon, will host tennis. Wembley Stadium will be used for football while Lord's cricket ground will play host to archery. London, ready to showcase their historic sites and a few new-classics as it plays host to the world this summer.

(CNTV April 18, 2012)