As a licensed guide for Washington, D.C., I've often been asked what the oldest monument in the city is. Well, may I present to you one of 40 sandstone monuments, and also the oldest in the U.S.
Dubbed the Boundary Stones, they were placed in 1791 and 1792 by surveyors Andrew Ellicott and Benjamin Banneker to mark the official boundaries of the newly formed capital. The stones run along the original diamond-shaped border at one-mile intervals.
On one side, the stones are engraved with "Jurisdiction of the United States" and on the opposite either "Maryland" or "Virginia." The other two sides bear the year the stone was placed and the compass variance. Although some have been lost, destroyed, replaced, or repositioned, history buffs have taken to finding the rest in the suburbs of Maryland and Virginia. The stone pictured is at the northwest border of Washington and Maryland, next to a bus stop. To find the rest, visit the Boundary Stones website.