National Register of Historic Places
U.S. Naval Observatory, U.S. Naval Observatory and Hydrographical Office
Washington, District of Columbia County, District of Columbia
The record
- Listed
- August 4, 2025
- Type
- Historic district
- Address
- 3450 Massachusetts Avenue. NW, Washington
- County
- District of Columbia
- State
- District of Columbia
- Reference number
- 100010550