An ancient and mysterious structure discovered under the Baltic Sea. The mysterious construction measures one kilometer long and would be about 10,000 years old.
Scientists believe the structure is a wall, perhaps to aid the efforts of the hunter-gatherers who inhabited the region so many years ago. Hundreds of colossal stone structures have been found scattered from the lava fields of the Saudi Arabian desert to central Asia. The data collected revealed a long stretch of about 1,670 individual stones, spanning about 971 meters.