Millennium bridge, London. This bridge became famous for its wobble. It measures 320m in length and is unusual as it uses lateral suspension to support the deck of the bridge. The wobble was caused by the natural frequency of the structure. Small movements in the deck caused large numbers of people to walk in step, which amplified the oscillation. The solution to this problem was to install shock absorbers to dampen out any oscillations before they were sufficiently large enough to influence people to walk in step. Photographed in London, UK.