Most of us go over bridges without giving them a second thought. But some bridges are engineering wonders and are extraordinary to behold. Put on your hard hat and go behind the scenes to find out how and why some of the world's most famous bridges were built. Explore the design, construction and engineering processes that went into creating some of these marvellous bridges. Extraordinary Bridges will leave you with a better understanding and a greater appreciation of these amazing structures. Part of the Exceptional Engineering series.