The City of Kitchener is a city in southwestern Ontario, Canada. It was the Town of Berlin from 1854 until 1912 and the City of Berlin from 1912 until 1916. The current population is 204,668. The metropolitan area, which includes the neighbouring cities of Waterloo and Cambridge, has 451,235 people, making it the eleventh largest Census Metropolitan Area (CMA) in Canada and the fifth largest CMA in Ontario.It is the seat of the Waterloo Regional Municipality, and is adjacent to the smaller cities of Cambridge to the south, and Waterloo to the north. Kitchener and Waterloo are often referred to jointly as "Kitchener-Waterloo" (K-W), although they have separate municipal governments. Including Cambridge, the three cities are known as "the tri-cities". The City of Kitchener covers an area of 136.86 square kilometres. In 2004, the city celebrated its 150th anniversary.