The Thousand Islands is the name of an archipelago of islands that straddle the Canada-U.S. border in the Saint Lawrence River as it emerges from the northeast corner of Lake Ontario. They stretch for about 50 miles (80 km) downstream from Kingston, Ontario. The islands, which number 1,793 in all, range in size from over 40 square miles (100 km2) to smaller islands occupied by a single residence, to even smaller uninhabited outcroppings of rocks that are home to migratory waterfowl. The number of islands was determined using the criteria that any island must be above water level all year round, bigger than one square foot (roughly 930 cm²), and support at least one living tree. The area is very popular among vacationers, campers, and boaters, and is often referred to as the "fresh water boating capital of the world".