The smallest of the five Great Lakes, Lake Ontario covers around 7,300 square miles and has over 700 miles of shoreline (half of which is on Canada’s side of the border). The lake was carved by the Great Glacier during the last Ice Age, about 10,000 years ago. As the glacier retreated northward, it etched great gouges in the earth and deposited massive boulders, as well. An important fishery and ecological habitat, there are over 300 miles of shorelines for adventurers to explore along with ten lighthouses, dozens of islands, and hiking trails.