Memorial signs placed in 2011 in Hyde Park in memory of the large exhibition held there.
5 plaques were placed in the park on a date celebrating 160 years of the royal parks
"The Great Exhibition of Industrial Works of All Continents" was a world fair aimed at showcasing the technological achievements (of the UK in particular).
The "Crystal Palace" building erected for the fair,
The "Crystal Palace" structure erected for the fair was designed in a very short time (5 days) and erected quickly (9 months).
Several years after the exhibition ended (in 1854) the building was dismantled and moved to the suburbs of London (Penge Common), until in 1936 it was destroyed by fire. The area is now called Crystal Palace after the building
Another board with details about the exhibition can also be found on the site Click for sign's details