After which Italian province is Parmesan named?

Parmigiano-Reggiano or Parmesan is an Italian hard, granular cheese produced from cow's milk and aged 12–36 months.

It is named after the producing areas, the provinces of Parma, Reggio Emilia, the part of Bologna west of the Reno, and Modena (all in Emilia-Romagna); and the part of Mantua (Lombardy) south of the Po. Parmigiano is the Italian adjective for Parma and Reggiano that for Reggio Emilia.

Both "Parmigiano-Reggiano" and "Parmesan" are protected designations of origin (PDO) for cheeses produced in these provinces under Italian and European law. Outside the EU, the name "Parmesan" can legally be used for similar cheeses, with only the full Italian name unambiguously referring to PDO Parmigiano-Reggiano.

It has been called the "King of Cheeses" and a "practically perfect food".