Notre Dame has a bridge building contest every year for their Physic's class. The rules of this event is to build a bridge that weighs 100.0 grams or less and seeing how much weight is can handle before it breaks apart. This event is held by Balsa Bridge. You can access their website at:
Here are some pictures of last year's bridge building contest.
Here is a picture of a bridge breaking under too much weight
The current record holder is Matthew Sullivan.
Vancouver is a city with many interesting bridges. My favourite bridge is the Burrard Street Bridge.
Here is an interesting link from the Balsa Bridge website:
Here are some of the Sponsors: