As the pendulums tick past 10 p.m., another July day gently takes its leave of Lyon. Here and there, street lamps supplant the setting sun and its fleeing tones of ochre and orange. They start working the night shift, shining once more on the buildings, avenues and squares they last illuminated in the early morning light.

In Gerland, a former industrial site converted to a park, evening strollers are witness to a dazzling phenomenon: Under the multihued lamps, the place literally glows. Doorways are illuminated in yellow and mauve; alleyways in blue, red and violet. Trees and plants seem to bloom psyche­delically, changing colour according to the angle of observation.

Le Jardin Chromatique (chromatic garden) is the creation of Laurent Fachard. The most colourful of Lyon’s lighting designers, he seeks to extend daytime’s prismatic scatterings of light into night, going so far as to “make colours that don’t exist.” More than just a remarkable nocturnal spectacle, the Gerland lighting scheme is something of a psychosensory experience. It reflects a particular approach to combining light and night: Lyon is lit up not only to see better but to dream bigger.

The Ville de Lumière, as Lyon has been dubbed, shines far beyond its city limits. Lyon’s illumination engineers are exporting their science all over Europe, Cuba, Israel, even Vietnam. The city’s adoption of a Plan Lumière 15 years ago has attracted many an eye (several of them belonging to tourists). Driven by an alliance of political, financial and intellectual interests, this most enlightened strategy was originally designed to showcase Lyon’s rich architectural heritage (which enjoys Unesco protection) while enhancing the city’s functional lighting.

Fachard says the plan “created a true cultural revolution. Lyonnais began to rediscover their cityscape. They thought it was beautiful and enjoyed going out at night to admire it.” On December 8, hundreds of thousands take to the streets for the Fête des Lumières (the official name dates from 1999, but the annual tradition goes back to 1852).