The Heyden Observatory at Georgetown University is the third oldest observatory in the country. The observatory was the site from which the city of Washington was surveyed, and was the home of some of the nation’s most influential astronomers until the second half of the twentieth century when the program was shut down.
On a personal note, I managed this observatory while I was in school and I believe that it is one of the most underrated gems on campus. Please vote for the observatory to receive funds from Partners in Preservation using the link below.
