As London prepared for its lavish XXX Olympiad this year, the host city was offered a rare chance to reinvent itself. And when the 2012 games kicked off, East London boasted a new cable car, the Royal Docks had been redeveloped, and the city had added several gleaming skyscrapers to its skyline. But this is not the first time that London has grown overnight. The tail end of the 19th century was also a period of rapid urban development -- one in which many of the landmarks that now define the city were constructed. Here's a look back at the last time London went through a radical transformation.