Mellon Square is an urban park in Downtown Pittsburgh, Pennsylvania. It is the first Modernist park built above a parking garage. With its distinctive black, white and green geometric pavement, it is a prominent urban oasis and gathering spot in Downtown Pittsburgh.The square, bounded by Smithfield Street, William Penn Place, and Oliver and Sixth Avenues, is surrounded by prominent downtown buildings including the Oliver Building, 525 William Penn Place, Omni William Penn Hotel, and the Regional Enterprise Tower. It has long been a popular lunchtime destination for downtown workers. In addition, retail shops are housed underneath it, along the Smithfield Street side of the square.
