Grateful, the city began constructing a statue of the Virgin Mary, one that would stand on top of the bell tower of the Fourvière Basilica overlooking the town below. The installation was planned for September 8, 1852, but divine intervention struck -- this time in the form of a flood. The River Saône overflowed and the event was postponed until December 8, which was also problematic thanks to a horrendous storm. Undeterred by the inclement weather, the Lyonnais waited for the storm to let up and placed lanterns in their windows in lieu of the cancelled fireworks. The spontaneous celebration caught on, became an annual occurrence, and took on even more significance when the Catholic church decreed December 8 the Feast of the Immaculate Conception two years later. And the rest, as they say, was history.
Nowadays? You'll still see candles twinkling in windowsills, but the festival has become a technological wonder in recent years -- one featuring over 70 professional light installations, massive illuminated sculptures, interactive displays, and contemporary performance art. An estimated 3 to 4 million people attend each year, gathering in the streets to admire the swirling, colorful projections transform building façades into psychedelic animations.