What is the role of Rideau Hall in Canadian government?

Rideau Hall is the official residence and workplace of the Governor General of Canada and one of the two official residences of the King when he is in Canada. The mansion and its 79-acre grounds are on Sussex Drive in Ottawa, Ontario, about 3 kilometres northeast of Parliament Hill. Rideau Hall has served as the vice-regal residence since 1867, when Queen Victoria's representative Viscount Monck moved into the building. The estate is a National Historic Site of Canada, designated in 1977.

The original house was built between 1838 and 1842 by Thomas McKay, an Ottawa entrepreneur and stonemason. The federal government leased the property in 1867 and purchased it in 1868. The mansion has been substantially expanded several times, with the current 175-room building the result of additions in 1873, 1885, 1913, and 1972. Major rooms include the Entrance Hall (with the Royal Coat of Arms), the Tent Room (used for state events and modelled on a Persian tent), the Ballroom (used for investitures of the Order of Canada), and the Reception Hall.

Rideau Hall hosts thousands of state and ceremonial events each year. Notable events include the swearing-in of the Prime Minister and Cabinet, presentation of credentials by foreign ambassadors, the Governor General's investitures of the Order of Canada and other federal honours, royal tours by visiting members of the British and Canadian royal families, state visits by foreign heads of state, and meetings of the Privy Council. The estate is open to the public for tours, with about 200,000 visitors per year.

The Citadelle of Quebec is the secondary official residence of the Governor General, located within the fortified walls of Quebec City. The Governor General spends a portion of each summer at the Citadelle and uses it for state events relating to Quebec and Atlantic Canada. The Citadelle has been the secondary vice-regal residence since 1872 (originally to give Quebec equal representation in the new federal capital arrangement). The federal Roads to Confederation Tour (operated by the National Capital Commission) connects Rideau Hall, the Parliament Buildings, and other federal heritage sites in the National Capital Region. Notable Governors General buried on the grounds of Rideau Hall include the wife of Lord Monck (Frances), whose son Frederick is interred in the Mackay-Monck graveyard.