The province of Turin is part of the Piedmont region. The capital of what is officially called the Città Metropolitana di Torino is Turin itself. The province consists of 131 municipalities, of which the capital is by far the largest. Most of the area is mountainous.
Province of Turin travel guide
Turin

Turin is the capital and largest city of the province. It is one of Italy’s most important industrial cities, largely because it is the home of FIAT. Much of its population is originally from the south. Thanks to the former presence of the House of Savoy, there are several royal palaces.
Collegno
Collegno is located directly to the west of the capital of the province. Population growth in both cities has been so big that they have formed a conurbation. It is best known because of its late 19th century Villaggio Neumann, an innovative district created for its factory workers.
Nature reserves
Along its northern borders, the province contains part of the Gran Paradiso massif and its highest peak is little over 4,000 metres. The Gran Paradiso National Park and the Sacro Monte Natural Reserve are the better known natural reserves.