A visit to this university comes with more than a tour of the library. 

In 1960, during the height of the Cold War, Columbia University was granted permission to begin working on a nuclear reactor. It was not, like the Cyclotron which is now dismantled and gone, part of the Manhattan Project. In fact, the reactor was never fueled and was never radioactive.

Issues with permits stopped the use of the reactor in 1972. The reactor was removed from Pupin. There is no longer any trace of it. However, inside Pupin Hall is a plaque acknowledging the hall as a National Historic Landmark because of its exceptional historical value.