High Quality Content by WIKIPEDIA articles! Downtown Pittsburgh, officially called the Golden Triangle or Central Business District, is the urban downtown center of Pittsburgh. It is located at the confluence of the Allegheny River and the Monongahela River whose joining forms the Ohio River. The "triangle" is bound by the two rivers. The area features offices for major corporations such as PNC Bank, U.S. Steel, PPG, Bank of New York Mellon, Heinz, Federated Investors and Alcoa. It is where the fortunes of such industrial barons as Andrew Carnegie, Henry Clay Frick, Andrew Mellon and George Westinghouse were made.