The Great Exhibition of the Works of Industry of All Nations was a one-time world's fair held in London's Crystal Palace (Hyde Park) from May 1 to October 15, 1851. It closed permanently after 5.5 months. The Crystal Palace was later moved to Sydenham and burned down in 1936. You can visit the site in Hyde Park (marked by a plaque) or see artifacts at the Victoria & Albert Museum, but the exhibition itself is history.