In 2011, a Swedish diving team searching for shipwrecks discovered a massive, circular formation deep beneath the Baltic Sea.

Add Yahoo as a preferred source to see more of our stories on Google. "It’s sad, one minute you're making the Kessel Run in less than twelve parsecs, the next you're at the bottom of the Baltic Sea." ...

When sonar first picked up a massive, stair‑like object on the floor of the Baltic Sea, the image looked less like geology and more like a movie prop. The structure’s circular outline, sharp edges and ...