The Great Lakes are hiding something nobody talks about. Decades of shipwrecks, lost aircraft, and even submerged secrets lie beneath their freezing waters.

The Great Lakes system is the largest freshwater system on Earth, holding about 21 percent of the planet’s surface fresh water. The five lakes — Superior, Michigan, Huron, Erie, and Ontario — span a combined surface area of roughly 94,000 square miles and drain northeast through the St. Lawrence River into the Atlantic. Their combined shoreline, including islands, runs about 10,000 miles.Michigan…