Fort Reno Park Fort Reno Park is a park in the Tenleytown neighborhood of Washington , D . C . . It is the highest point in the city , and was involved in the only Civil War battle to take place in the District of Columbia . The highpoint was resurveyed and a new USGS Benchmark was placed in 2007 at coordinates N 38 . 95198 and W 77 . 075922 , a location open to the general public and outside the fenced area where the highpoint was previously believed to be . Fort Reno , at 409 feet , is actually lower than the top of the Washington Monument , which rises 555 feet from nearly sea level . However , the sandstone castle - like fort structure on top and highpoint antenna farm raise the height above that of the monument . Construction . In early August 1861 , engineers under Major John G . Barnard , in charge of the defenses of Washington , chose the highest point in the District of Columbia for the construction of a fort , with construction starting in earnest in August 1861 with the arrival of McCall ' s Division of Pennsylvania Reserves . " The Utica Morning Herald " ( NY ) of December 16 , 1862 gives credit for the building of the fort specifically to the Ninth Regiment Pennsylvania Reserves , however it is known that other regiments of McCall ' s division were engaged in its construction and that of other forts in the vicinity . At the time the structure was named Fort Pennsylvania and was only renamed Fort Reno in 1863 in honor of Major General Jesse Lee Reno who died at the Battle of South Mountain in 1862 . It was one of a string of forts circling Washington to defend it against the Confederates . Work on the fort was continued by the succession of regiments stationed at the Tennallytown encampment after McCall ' s division moved to Langley on October 9 , 1861 . Of these regiments the 119th Pennsylvania is popularly given credit for having " built the fort " in August and October 1862 , however , Fort Pennsylvania had been worked on prior to the 119th Regiment ' s arrival by the regiments of Peck ' s Brigade ( which were stationed at Tennallytown from October 1861 through to March 1862 ) , the 59th New York and the 9th and 10th Rhode Island Regiment s , amongst others . Eventually the fort had a dozen heavy guns and a contingent of 3 , 000 men , making it the largest fort of those surrounding Washington . Civil War Combat . The fort saw action on July 10 – 12 , 1864 , when Robert E . Lee sent 22 , 000 Confederates led by General Jubal A . Early against the 9 , 000 Union troops defending Washington ( Ulysses S . Grant had depleted the Union defenses for his siege of Petersburg ) . The Confederates attacked from the north in Maryland . The initial warnings came from Fort Reno lookouts spying movement by Rockville . The attack itself was directed about 4 miles to the east across Rock Creek at Fort Stevens . The battle is known as " The Battle of Fort Stevens . " Following the war the fort became a " Freetown " for freed slaves and later a reservoir . Park . Fort Reno is now maintained by the National Park Service , and includes a baseball field , several tennis courts , and large grass field areas . However the reservoir itself including the sandstone castle are off - limits to the public . Residents gather here on the 4th of July to look down on the several annual fireworks displays over Montgomery County , Maryland and Northern Virginia that are visible from the western slope of the park . Music Venue . Now Fort Reno is the location of an annual free summer concert series , featuring bands from the area ' s indie rock scene . Bands including Teen Idles , Fugazi , The Dismemberment Plan , Q and not U , Ted Leo , Benjy Ferree , Canyon , Travis Morrison , The Most Secret Method , Beauty Pill , and Power Pirate have played there . On May 14 , 2008 Fort Reno Park was closed due to the detection of arsenic in the soil , and a fence was erected around the park . However on May 28 the park was reopened and the fence removed after officials found that the initial high reading of arsenic levels was mistaken .