9. The Devil’s Kettle

A few miles away from the US-Canada Border is Minnesota’s Judge C.R. Magney State Park. The Brule River flows through this park, falling onto several rocks and creating several waterfalls. While one half of this water then flows on to join Lake superior as water normally does, the other half falls into a deep hole (named The Devil’s Kettle) that apparently leads no where. Researchers have even dumped dye, ping pong balls, and logs to see where it might turn up, but no luck. So, where does all that water go? No one knows!