Wumen Bridge [Suzhou]

Traidtional Chinese bridges and other buildings are all truly wonders of architecture. These were built decades ago, without the use of nails. In fact, using nails in construction was an alien concept to the Chinese, and nails were known as "yang ding" ("yang" means western). The arc bridges built by the Chinese all made use of Physics theories to support the structure and load. The picture here shows the Wumen Bridge, one of the highest arc bridges in Suzhou.