Turin is a city and major business and cultural centre in northern Italy, capital of the Piedmont region, located mainly on the left bank of the Po River, in front of Susa Valley and surrounded by the western Alpine arch. The population of the city proper is 911,823 (dicembre 2012) while the population of the urban area is estimated by Eurostat to be 1.7million inhabitants. The Turin metropolitan area is estimated by the OECD to have a population of 2.2million. The city has a rich culture and history, and is known for its numerous art galleries, restaurants, churches, palaces, opera houses, piazzas, parks, gardens, theatres, libraries, museums and other venues. Turin is well known for its baroque, rococo, neo-classical, and Art Nouveau architecture.