1893 – Penn Station, Pittsburgh

Pittsburgh’s central train station, built in 1893, was designed by Daniel Burnham, a Chicago architect who also designed New York’s iconic Flatiron building. The Rotunda is the highlight of the structure; it served as a passenger waiting area and a turnaround space for carriages. The structure of the dome is similar to the ancient Pantheon in Rome. The station underwent a major restoration in 1980.