’Underwater Stonehenge’ found in Baltic Sea - mystery surrounds 10,000-year-old megastructure

A few kilometres off the coast of northeastern Germany, researchers have found a stone wall up to 11,000 years old at a depth of 21 metres in the Baltic Sea. The stone wall caught the eye of marine geologist Jacob Geersen when he was conducting seabed surveys with students from the University of Kiel for training purposes. A year later, he returned to the site, about 10 kilometres off the coast of the seaside resort of Rerik, with research divers and prehistoric researchers from the University of Rostock. Using echo sounding, Geersen and his team can reconstruct the topography of the area at different time periods. He hopes to one day be able to say how the stone wall fits into the landscape of the time. Prehistoric researchers are certain that the wall is at least 10,000 years old, but more likely 11,000. Because of the rise in sea level, the wall must be at least 8500 years old. But 8500 years ago the area was forested and it would not make sense to build a wall in