According to this scientist there are thousands of these tunnels dating back 12000 years, not all interconnected but spanning from Scotland to Turkey. He believes they were used to travel safely over long distances from the predators of the day.

“German archaeologist Dr Heinrich Kush states that evidence of huge underground tunnels has been found under dozens of Neolithic settlements all over the European continent. These tremendous tunnels are often referred to as ancient highways.”

The story is interesting, but the evidence seems a bit weak. Give it s read see what you think!

Ancient Superhighways: 12,000-Year-Old Massive Underground Tunnels From Scotland To Turkey