The Black Sea is a marginal sea of the Atlantic Ocean lying between Europe and Asia; east of the Balkans in Southeastern Europe, south of the East European Plain in Eastern Europe, west of the Caucasus, and north of Anatolia in Western Asia. The Black Sea is bordered by Bulgaria, Georgia, Romania, Russia, Turkey, and Ukraine. It has a positive water balance with an annual net outflow of 300 km3 (72 cu mi) per year through the Bosporus and the Dardanelles into the Aegean Sea.

Lake Superior is the largest of the Great Lakes of North America, the world's largest freshwater lake by surface area, and the third-largest freshwater lake by volume. It is shared by Ontario to the north, Minnesota to the west, and Wisconsin and the Upper Peninsula of Michigan to the south. Superior is the farthest north and west of the Great Lakes chain, and the highest in elevation, draining through the St. Mary's River into Lake Huron.