Allegheny Commons is a municipal park located in Pittsburgh's North Side. The park surrounds the neighborhood of Allegheny Center. Dating to 1867, it is the oldest park in the city of Pittsburgh. The park was once free grazing land which surrounded the first 32 blocks of Allegheny City in John Redick's 1784 town plan. It was re-made into a municipal park in the 1860s by landscape architects hired by Allegheny City.
Allegheny Commons Park has three main parts, all of which are in the Allegheny Center neighborhood: Allegheny Commons Park West Park, Allegheny Commons Park North Park, and Allegheny Commons Park East Park. The West Park portion is the largest of the three, and it has housed the National Aviary since 1952.