Big Round Top Big Round Top is a boulder - strewn hill notable as the topographic high point of the Gettysburg Battlefield and for 1863 American Civil War engagement s for which Medals of Honor were awarded . In addition to battle monuments , a historic postbellum structure on the uninhabited hill is the Big Round Top Observation Tower Foundation Ruin . Geography . Big Round Top is the southern peak of the Gettysburg Battlefield and is within the area encompassed by a drainage depression ( southeast , south ) , Plum Run ( west , north ) , and the Crawford Rd / Wright Av roadway ( north , northeast ) . In addition to Little Round Top , adjacent battlefield locations are South Cavalry Field / Slyder Field ( west ) , Devil ' s Den ( northwest ) and the Valley of Death / Slaughter Pen ( north ) . The hill is the highest point of an Adams County dendritic ridge which Plum Run divides at Big Round Top ( the drainage divide continues to the east ) . In addition to Little Round Top ( 650 ) , nearby heights are Warfield Ridge ( west ) , hills of ~ 580 ft ( southwest ) and ~ 540 ft ( northwest ) , and Houck Ridge ( north - northwest ) ; while Carr Hill ( 876 ft ) is the nearest higher hill . " Devil ' s Kitchen " is rock formation and small cave on the lower slopes of Big Round Top . History . The igneous hill was formed 200 million years ago when the " " outcrop of the Gettysburg sill " " intruded through the Triassic " Gettysburg plain " . Subsequent periglacial frost wedging during the Pleistocene formed the hill ' s extensive boulders . Early human activity included Indigenous people clearing an area on the slope of Big Round Top prior to the 1736 British purchase of the region . Civil War . Privately owned during the Battle of Gettysburg , Big Round Top ' s slope , timber , and boulders precluded placement of artillery on the summit . At various times during the 1863 battle , positions on Big Round Top formed the left flank of the Union defense . By September 1863 , David McConaughy had begun to acquire a portion of Big Round Top for battlefield preservation . The Elon J . Farnsworth monument was erected before 1896 at the base of Big Round Top , and statues of William Wells ( 1931 ) and John Michael Tobin are also on the hill . Postbellum . Kilpatrick Avenue had been completed at the west base of Big Round Top by 1895 when the gravel South Confederate Avenue was constructed across the northwest slope . In 1903 , Wright Av was constructed along the northeast slope , and in 1937 , S Confederate Av and the Plum Run stone bridge were rebuilt for the 75th battle anniversary and reunion . In 1940 , Seminary Ridge CCC workers rerouted the stone trail to the Big Round Top summit , and Harry Truman visited Big Round Top in 1946 . In 1964 , the Big Round Top Nature Trail was created around the hill and provided access to the Devil ' s Kitchen . The 1895 Big Round Top Observation Tower was dismantled in 1968 and the foundation was named a historic ruin in 2004 . Observation Tower . The tower was built in the late 19th century . Fred Lyons of Baltimore led the construction team that moved the foundation ' s granite blocks to the Big Round Top summit using block and tackle driven by a 12 horsepower engine . Constructed on the Gettysburg Battlefield ' s highest hill , the Big Round Top tower was to be replaced for the 1938 anniversary reunion by a stone " Gettysburg Peace Memorial " with a 75 - foot - high observation deck above the summit and a flame 30 feet higher . ( The memorial was instead erected on Oak Hill . ) Destruction . During 1968 tower maintenance , the Schlesser Demolition Co dismantled the Big Round Top tower as uneconomical due to " " its condition and the very limited use " [ due to an uphill , lengthy , and serpentine trail . ] " Most who started the climb gave out enroute , and upon reaching the tower decided against continuing the climb to the top of the metal observatory " " ( GNMP Superintendent George F . Emery ) . The foundation ruin ( park structure RU05 ) of the " national landmark " tower , was " entered - documented " as a historic site on January 23 , 2004 .