Canada is the second-largest country in the world, covering over half of the Northern Hemisphere. From east to west, Canada covers 4,700 miles (7,560 kilometers) of North America from the Atlantic to the Pacific, spanning six time zones. Its northern border is the Arctic Ocean, and it shares a border with the United States to the south. Canada is known for its coastal and territorial waters. Its lakes and rivers contain 20 percent of the world's freshwater supply, and it boasts the world's longest coastline. The country's interior houses the majestic Rocky Mountains, vast boreal forests, tundras, rolling plains and the Canadian Shield, a hilly, swampy region where scientists have found some of the oldest geological formations in the world.

Source: How Stuff Works