The area contains over 10,000 lakes which were formed by glaciers some 11,000 years ago during the end of the last ice age. In the heart of the Ontario lake country are the two areas known simply as "Muskoka" and "Haliburton" (which are both actually a district or county respectively). To most people in Ontario, the area is simply part of what is known as cottage country, in reference to the some 250,000 summer cottages on the lakes of southern Ontario.