Rideau Hall is, since 1867, the official residence in Ottawa of both the Canadian monarch and the Governor General of Canada. It stands in Canada's capital on a 0.36 km (88 acre) estate at 1 Sussex Drive, with the main building consisting of 170 rooms across 9,500 m (102,000 ft), and 24 outbuildings around the grounds. While the equivalent building in many countries has a prominent, central place in the national capital (Buckingham Palace, the White House, and the Royal Palace of the Netherlands, for example), Rideau Hall's site is relatively unobtrusive within Ottawa, giving it more the character of a private home.
Most of Rideau Hall is used for state affairs, only 500 m (5,400 ft) of its area being dedicated to private living quarters, while additional areas serve as the offices of the Canadian Heraldic Authority and the principal workplace of the governor general and his or her staff — either the term Rideau Hall, as a metonym, or the formal idiom Government House is employed to refer to this bureaucratic branch. Officially received at the palace are foreign heads of state, both incoming and outgoing ambassadors and high commissioners to Canada, and Canadian crown ministers for audiences with either the viceroy or the sovereign, should the latter be in residence. Rideau Hall is likewise the location of many Canadian award presentations and investitures, where prime ministers and other members of cabinet are sworn in, and where federal writs of election are dropped, amongst other ceremonial and constitutional functions. The house is open to the public for guided tours throughout the year; approximately 200,000 visitors tour Rideau Hall annually.
Rideau Hall and the surrounding grounds were designated as a National Historic Site of Canada in 1977.