Pittsburgh is a city in the southwest of the US state of Pennsylvania, located at the confluence of the Allegheny and Monongahela rivers, which combine to form the Ohio River. It had a population of 302,971 as of the 2020 census, and is the anchor of the Pittsburgh metropolitan area, the second-largest in the state with a population of 2.37 million. Pittsburgh is known as the "Steel City", as a result of its more than 300 steel-related businesses and also the "City of Bridges", for its 446 bridges. Named in 1758 in honor of British statesman William Pitt, the city developed as a vital link of the Atlantic coast and Midwest, as the mineral-rich Allegheny Mountains led to the region being contested by the French and British empires, Virginians, Whiskey Rebels, and Civil War raiders. This picture shows a skyline panorama of Pittsburgh at night, taken from Mount Washington.Photograph credit: Dllu