of the governor general
, at One Sussex Drive
Thomas MacKay, a mason and mill-owner from Scotland, built the first building in 1838. He named it Rideau Hall after the river and canal system that created both Ottawa and MacKay's fortune. The government of Canada bought it when Queen Victoria chose Ottawa as the capital in 1857, and the first governor general, Viscount Monck, moved in in 1866.
The house was big, but not big enough for the truly massive parties the governor of a wealthy dominion was expected to hold, and the entourages of visitors he was expected to host. The government added a residential wing the same year the Moncks moved in, a ballroom and indoor tennis court in 1872, and a new façade and foyer in 1913.
The building itself is large, but it's only a small part of the 79-acre estate, which is a longish walk but quick bike-ride or drive from downtown Ottawa, in the middle of the fancy-pants embassy district. The estate is open to the public; it's gorgeously landscaped, with lots of grass and well-tended trees. (The head gardener, Ed Lawrence, is a regular on gardening shows on radio and television and appears to know literally everything there is to know about the plants that grow in Ottawa's climate.) Governor General Jeanne Sauvé closed the grounds for "security reasons" in the 1980s -- she was tired of people looking in her windows -- and it was a scandal. Her successor re-opened the estate to great public acclaim.
Although there are grenadier guards in red uniforms and bearskin hats as ceremonial guards and Mounties in Rideau Hall itself, the only serious impediment to getting to the home of Canada's head of state is a commissionaire with a traffic cone in the middle of the driveway. That commissionaire is as good a symbol of Canada as any, I think.
The governor general funds a free summer concert series on the grounds of Rideau Hall, featuring Canadian acts. Perhaps surprisingly, it doesn't suck.