Many visitors to Paris ask if its nickname is the City of Light, or if it is the City of Lights. The short answer is that both terms are correct, for different reasons. Visitors also ask how the city acquired its monikers, and there are several explanations. In 1670, the lieutenant general of police of Paris tried to make the city a safer place at night. He instructed the distribution of lit candles and lanterns throughout the city to illuminate its dark streets and he required residents to place lit lanterns behind their windows. The term “Paris, Ville Lumière” propagated, and that translates as Paris, City of Light. It is also true that Paris was a centre of intellectual activity during the Age of Enlightenment, which began in the 17^th century and stretched into the 18^th. It is when philosophers, thinkers and intellectuals such as Voltaire and encyclopaedists like Diderot gathered in Paris. The city became known as one of intellectual enlightenment, where the light was measured in terms of rational thought, not lumens. Hence, City of Light. In the 1820’s Paris installed a vast network of gas lighting for its streets. During the decade that followed, visitors from England and other countries were impressed, and they coined a nickname for the French capital, City of Lights. Choose the term that you like best. But, at the risk of confusing you, note that when the French use the term “Ville des Lumières” (City of Lights), they refer to France’s second largest city, Lyon, not to Paris.