Pittsburgh is the American city in Allegheny County, Pennsylvania. The city was founded by the French and it received city rights and in 1816. Pittsburgh is sometimes called the "City of Bridges", in the center itself there are as many as ten of them. The Andy Warhol Bridge that is painted yellow, also known as Seventh Street Bridge, is one of them. This suspension bridge spans the two banks of the Monongahela River. It was opened in 1926. In downtown Pittsburgh there are numerous skyscrapers. The characteristic black U.S. Steel Tower is the highest of them.