Mellon Square is an urban park in Downtown Pittsburgh, Pennsylvania, United States. 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.

Downtown Pittsburgh, colloquially referred to as the Golden Triangle, and officially the Central Business District, is the urban downtown center of Pittsburgh, Pennsylvania, United States. It is located at the confluence of the Allegheny River and the Monongahela River whose joining forms the Ohio River. The triangle is bounded by the two rivers.