The Greater Toronto Area (GTA) is a metropolitan area in Canada. The Greater Toronto Area is defined as the central city of Toronto, and the four regional municipalities that surround it: Durham Region, Halton, Peel, and York Region. The regional span of the Greater Toronto Area is sometimes combined with the city of Hamilton, Ontario and its surrounding region, to form the Greater Toronto and Hamilton Area. The Greater Toronto Area is the northern part of the Golden Horseshoe.
The Greater Toronto Area covers a total area of 7,125 km2 .It is bordered by Lake Ontario to the south, Kawartha Lakes to the east, the Niagara Escarpment to the west, and Lake Simcoe to the north. Parts of the region remain farmland and forests, making it one of the distinctive features of the geography.