The Olympic games hope to regenerate a poor part of London and make it better with jobs, homes, shops and transport links. These will last for a hundred years or more, not just for a few weeks in the summer. The different buildings and sports stadiums are all going to be used after the games finish.
The New Olympic Stadium
The main athletics stadium can hold 80,000 people. In the Olympic Games it will host the opening ceremony, the closing ceremony and the athletics events. After the Games it can be made smaller to 60,000 seats or even 25,000 seats.
The new velodrome is a big indoor track for all the cycling events in the Olympics. Britain is quite good at cycling and won several gold medals in Beijing in 2008. It is important to encourage cycling because it is a healthy and environmentally-friendly activity. So, after the Games the velodrome will be made into a bigger velopark with a mountain-bike circuit and a road-racing track.
The Athletes' Village
The new athletes' village will be big enough for all the people taking part in the Olympics. When the games finish, the whole village will be changed into houses open to everyone. There will be enough space for 3,000 families. The schools and hospitals for the people who will live there in the future have already been built.
We know that there will be lots of great sporting action next year, but, how will we know if the London 2012 is successful in the future? The only way will be to come back in a hundred years and see if the buildings are still being used.