- 1 inch diameter
- Cast in fine pewter
- Lanyard hook attachment
- Mounted on story card
Elevation: 555 ft.
Coordinates: N38° 53' 22.08377'' W77° 02' 06.86378''
Location: District of Columbia, USA
National Mall, Washington DC, USA This beloved and well-known monument is the world's tallest free-standing masonry structure; it is arguably the nation's most recognized landmark and stands as a tribute to freedom. Little recognized is the fact it also functions as a survey monument. Upon completion by the US Corps of Army Engineers in 1884, scaffolding was mounted around the apex of the massive structure. From there, survey measurments of the surrounding vicinity were made - an appropriate use of the monument to George Washington a surveyor in his youth.
In August, 1999, during the restoration of the monument, the National Geodetic Survey made GPS observations from its apex and established precise position and elevation measurements. Several other significant points were observed including the Zero Milestone, the Meridian Stone of 1890, and the Jefferson Stone (marking the nation's first meridian).