What city is nicknamed and most commonly called "The City of Light"?

Paris, France, is the city most commonly referred to as "The City of Light". It is often called "The City of Light" (La Ville Lumière), both because of its leading role during the Age of Enlightenment, and more literally because Paris was one of the first European cities to adopt gas street lighting. In the 1860s, the boulevards and streets of Paris were illuminated by more than 56,000 gas lamps.

In Paris, gas lighting was first demonstrated in November 1800 at a private residence on the rue Saint-Dominique, and was installed on a covered shopping street, the Passage des Panoramas, in 1817. The First gas lamps on the streets of Paris appeared in January 1829 on the place du Carrousel and the rue de Rivoli, then on rue de la Paix, place Vendôme, rue de Castiglione; by 1857 the Grands Boulevards were all lit with gas. As a result of the gaslights being installed on the boulevards and city monuments in the 19th century, Paris was then given the nickname "The City of Light."