Old Naval Observatory

The Old Naval Observatory is a former Observatory in Washington, DC, which was used from 1844 to 1893 by the United States Navy. Under the direction of Matthew Fontaine Maury, it became one of the most prestigious international research institutes in the field of oceanography.

The building remained in the possession of the Navy, which from 1894 to 1902, the Naval Museum of Hygiene operating there. From 1903 it was used as a hospital and remained in use until the National Naval Medical Center was completed in 1943. Today, it is an administrative building of the Surgeon General of the United States Navy and not publicly available.

January 12, 1965, is a National Historic Landmark.