Two doughs and a buffalo
Pizza, pasta and mozzarella are not souvenirs: they are three real industries, all born within fifty kilometres of each other.
Of all Italy's regional cuisines the Campanian one is the most exported, to the point that three of its dishes have become shorthand for Italian food across half the world. Which makes it hard to see it for what it is: a poor cuisine from rich land, where meat was rare and the tomato changed everything in two centuries.
Pizza
Neapolitan pizza is a precise thing: a dough of nothing but flour, water, salt and yeast, a long rise, a wood oven, under ninety seconds of baking. The rim swells and blisters black, the middle stays soft enough to fold. Since 2017 the art of the Neapolitan pizzaiuolo has been on the UNESCO list of intangible heritage, and the classics remain two: marinara and margherita.
Buffalo mozzarella

It is made with buffalo milk, not cow's, and the buffalo have been in the damp plains of the Volturno and the Sele since those lands were marsh. It carries DOP status and an unwritten rule that matters more than the mark: eat it the same day, at room temperature, with nothing on it. Bought from a dairy in the morning it is a different thing from the supermarket version.
The tomato
The San Marzano grows in the Nocera and Sarno countryside, on volcanic soil, and it is the preserving tomato that made the fortune of Neapolitan cooking. It is long, with little water and few seeds, and it peels easily: which is why it ends up in a tin rather than in a salad. The rule in the kitchen is that a San Marzano sauce needs no sugar.
The wines of Irpinia
Campania's serious wines do not come from the coast but from the hills inland, and there are three with guaranteed status: Taurasi, an aglianico red that will take twenty years in the bottle, and the two whites, Greco di Tufo and Fiano di Avellino. Anyone passing through Irpinia finds them at the winery for prices that do not exist on the coast.
Mozzarella is bought in the morning and eaten at lunch. The next day it is something else.
The rule no regulation writes down