An archetypal icon of London, especially when illuminated at night, Tower Bridge was opened after 8 years of construction in 1894 by the then Prince of Wales, following a massive industrialisation of East London.
The bridge's designer, Horace Jones, was the winner of a public competition to solve the problem of crossing the Thames in 1876: a river crossing was needed but large ships would still need to pass to the docks beyond, so the bridge was designed to be raised, incorporating two counterweighted bascules powered by huge steam engines.
The bridge stands 800 feet high with a span of 200 feet and can be raised in less than a minute despite the combined weight of over 2000 tons.
These days the bridge is electrically operated, although the original steam generators have been retained as a tourist exhibit. Tower Bridge is raised as many as five hundred times in a year.