of the Canadian monarchy and various viceroys (the governor generals and the lieutenant governors). Though not universal, in most cases the title is also the building's sole name; for example, the sovereign's and governor general's principal residence in Ottawa is known as Government House only in formal contexts, being more generally referred to as Rideau Hall. The use of the term Government House is an inherited custom from the British Empire, where there were and are many government houses. Rideau Hall is, since 1867, the official residence in Ottawa of both the Canadian monarch and his or her representative, the Governor General of Canada, and has been described as "Canada's house". It stands in Canada's capital on a estate at 1 Sussex Drive, with the main building consisting of approximately 175 rooms across , and 27 outbuildings around the grounds. While the equivalent building in many countries has a prominent, central place in the national capital, Rideau Hall's site is relatively unobtrusive within Ottawa, giving it more the character of a private home. Along with Rideau Hall, the Citadelle of Quebec, also known as La Citadelle, is an active military installation and official residence of both the Canadian monarch and the Governor General. It is located atop Cap Diamant, adjoining the Plains of Abraham in Quebec City, Quebec. The citadel is the oldest military building in Canada, and forms part of the fortifications of Quebec City, which is one of only two cities in North America still surrounded by fortifications. The fortress is located within the historic district of Old Québec, which was designated a World Heritage Site in 1985. In addition to the federal residences, most provinces maintain a residence for the Canadian monarch, as well as their provincial viceroys lieutenant-governors. There is no government house for the Lieutenant Governors of Ontario (repurposed in 1937 and demolished in 1961), Quebec (destroyed by fire in 1966), or Alberta (closed in 1938 and repurchased and repurposed in 1964). Mexico The capital of Mexico, Mexico City, is traditionally nicknamed the "City of Palaces"; a nickname usually attributed to Alexander von Humboldt after he visited the city in the late 18th century and early 19th century, but originally coined by Charles Latrobe, an English traveller who visited Mexico City in 1834 and "got the feeling of living a dream". In Central Mexico, the Aztec emperors built many palaces in the capital of their