Inspired by the stately presence of the Executive Mansion, this area maintains a decorous gentility, with manicured parks, elegant row houses and grandly conceived public structures. Lafayette Square, a 7-acre public park, lies just to the north of the mansion, and is often the scene of public demonstrations. The stately Treasury Building rises east of the White House; the colossal Old Excecutive Office Building stands just to the west. The Ellipse, the open greensward to the south, functions as a ceremonial ground; on its north is the Zero Milestone, from which all distances in the federal city are computed.