Like many tourists in Naples, I have only ever been there en route to somewhere else. For years the city has had a reputation for being dirty, dangerous and traffic-choked: why on earth would anyone choose to linger? But this has changed. Naples is becoming a destination in its own right, thanks in part to the huge popularity of the enigmatic author Elena Ferrante. And with the city’s rubbish-collection problem solved and new traffic restrictions in the centre, it is looking in better shape than it has done for decades.

Ferrante, who writes under a pseudonym, is the most important literary sensation to have emerged from Italy in a generation. Her quartet of Neapolitan Novels has sold more than 5.5 million copies worldwide. The New York Times observed that enthusiasm for the novels is so intense that it is being described in “epidemiological terms, making the phenomenon sound almost like an infectious disease”.