The survey team placed forty sandstone boundary markers at or near every mile point along the sides of the square (see: Boundary markers of the original District of Columbia). Thirty-six of these markers still remain. The south cornerstone is at Jones Point. The west cornerstone is at the west corner of Arlington County, Virginia. The north cornerstone is south of East-West Highway near Silver Spring, Maryland, west of 16th Street. The east cornerstone is east of the intersection of Southern Avenue and Eastern Avenue.