The Cathedral of Learning was designed by Charles Klauder, who fused the idea of a modern skyscraper with the tradition and ideals of Gothic architecture. The support structure of the Cathedral is steel, like that of a typical skyscraper, while the exterior and finishing details take their cues from the Gothic period.
Leading out of the Commons Room are a set of 18-foot ornamental iron gates crafted by master blacksmith Samuel Yellin in the 1930s. They were placed in 1940 and include a quote from poet Robert Bridges:
Here is eternal spring; for you the very stars of heaven are new.
Yellin also produced the ironwork railings seen around the room and other pieces in the Humanities Center, some of the Nationality Rooms, Stephen Foster Memorial, and Heinz Chapel.
The exterior of the Cathedral contains elements of Gothic style including the quatrefoil stonework detail on some of the window exteriors.