Several buildings on the Morningside Heights campus are listed on the National Register of Historic Places. Low Memorial Library, a National Historic Landmark and the centerpiece of the campus, is listed for its architectural significance. Philosophy Hall is listed as the site of the invention of FM radio. Also listed is Pupin Hall, another National Historic Landmark, which houses the physics and astronomy departments. Here the first experiments on the fission of uranium were conducted by Enrico Fermi. The uranium atom was split there ten days after the world's first atom-splitting in Copenhagen, Denmark.