Easily one of our readers favorite posts every week is Magnificent Metal Mondays. Today we travel down under to Australia to see the glorious Sydney Harbour Bridge. It is the world’s largest steel arch bridge with the top of the bridge standing 440 feet above Sydney Harbour. The bridge opened in March of 1932 and took approximately 8 years to build. A real interesting fact about the bridge is that the steel expands and/or contracts depending on whether it is hot or cold. This ultimately causes the bridge to not be completely stationary and can rise or fall up to 7.1 inch.