Four bridges in London were illuminated by dynamic LED displays, designed by American artist Leo Villareal, on Wednesday as the first phase of a 45-million-pound (56 million U.S. dollars) project to create the world's longest artwork. /VCG Photo

Another five bridges are expected to be lit up next year, followed by the remaining six, to create the "Illuminated River" project - around 6.4 kilometers from Tower Bridge to Albert Bridge - the longest public art commission in the world. /VCG Photo

It has been a long and complicated process to install all LED displays on these bridges since the designers need to take everything into consideration, including dealing with owners of the bridges as well as handling technical factors. /VCG Photo

"River Thames was London’s beating heart and the bridges the connecting arteries," Hannah Rothschild, who originated the project, told The Guardian. /VCG Photo