We'll admit: there's probably more than one Festival of Lights held around the world — and maybe even held December 6-9. But the one in central France is the only one that counts. With attendance measured in the millions, it's one of the largest celebrations in the world, as the entire city joins together and places candles along the outside of all the windows, paying homage to the Virgin Mary. While the candle ritual dates back to the 1600s, in modern days this old tradition is joined by a number of performances, light shows, and buildings — most notably the Basilica of Notre-Dame de Fourvière and Cathédrale Saint Jean-Baptiste — awash in color.