Fort DeRussy was an American Civil War-era fortification constructed in 1861 on a hilltop along the west bank of Rock Creek within Washington, D.C., as part of the Defenses of Washington.
Wikipedia https://en.wikipedia.org/wiki/Fort_DeRussy_(Washington,_D.C.)
Address Washington 20015, United States
Coordinates 38°57'47.803" N -77°3'3.393" E