They can be made with ingredients like San Marzano tomatoes , which grow on the volcanic plains to the south of Mount Vesuvius , and mozzarella di bufala Campana , made with the milk from water buffalo raised in the marshlands of Campania and Lazio in a semi-wild state ( this mozzarella is protected with its own European protected designation of origin ) .
Authentic Neapolitan pizzas are made with local ingredients like San Marzano tomatoes , which grow on the volcanic plains to the south of Mount Vesuvius and Mozzarella di Bufala Campana , made with the milk from water buffalo raised in the marshlands of Campania and Lazio in a semi-wild state ( this mozzarella is protected by its own European law ) .