Canada is home to more lakes than the rest of the world's countries combined. It is estimated that Canada has over 2 million lakes, with 563 of them being larger than 100 square kilometers. About 9% of Canada's total area is covered by fresh water. This abundance of lakes is a result of the last glacial period; as the massive ice sheets retreated, they carved out deep basins and left behind meltwater that formed the Great Lakes and millions of smaller bodies of water. This gives Canada the largest total surface area of fresh water on the planet, a vital resource for its ecosystem and economy.