The Italian town that gave Narnia its name in C.S. Lewis’s Chronicles of Narnia is Narni.
Lewis encountered the Latin form of the town’s name, Narnia, in an atlas when he was young. The name appealed to him, and he later used it for the fictional land at the heart of his children’s books. The connection is a name-source detail rather than a claim that the geography, culture, or history of Narnia directly reproduces the Italian town.
Narni is a hill town in the Italian region of Umbria. Its ancient Roman name was Narnia, and the modern Italian form is Narni. This makes the origin easy to confuse with a wholly invented word, especially because Lewis’s fantasy world has its own maps, kingdoms, rulers, and mythology.
The Narnia novels were published from 1950 to 1956. Their landscapes draw on many literary and mythological influences, but the specific name came from Lewis’s chance discovery of a real place-name in an atlas.