Pittsburgh, Pennsylvania, located at the confluence of the Allegheny, Monongahela, and Ohio rivers, has a rich history that dates back to the late 18th century. Originally a small frontier outpost, Pittsburgh became a center for industry and commerce during the 19th and 20th centuries. The city was a major producer of steel, thanks in part to its proximity to the coal and iron resources of the surrounding region. This led to Pittsburgh is known as the "Steel City" and the "Smoky City" due to the pollution caused by the steel mills. However, the city underwent a transformation in the 1980s, diversifying its economy and rebranding itself as a hub for technology and innovation. Today, Pittsburgh is home to some of the world's leading research institutions, including Carnegie Mellon University and the University of Pittsburgh. The city has also undergone a significant urban revitalization, with new developments such as the PNC Park and the David L. Lawrence Convention Center, attracting visitors from around the world.