Arneis is so important to Piedmont oenology that it is commonly called as the "white Barolo".
This vine is native of the Roero area but it gets produced also in other wine districts like the Langhe region.
Administratively, Piedmont is divided into provinces: Turin is the regional capital, Vercelli is the rice town, Asti and Cuneo are the areas with the amazing good food and wine culture, Biella is the cashmere area, where Zegna is from, Alessandria also famous for its vineyards (Gavi!!), Novara (rice and gorgonzola cheese) and Verbania.
Wine wise though, Piedmont is divided into growing areas. The richest one (in products) is Langhe in the Cuneo province, near Asti. The capital of the Langhe area is Alba where Nutella is also from. As you can see, Roero is a small hilly area northern of Alba.