Ancient Tunnel System UK to Turkey

 

Possibly connecting to the city below ground in Turkey. Possibly connecting  to the oldest known temple in turkey.

 

 

The answer to this riddle is easy. The reason they built this extensive tunnel system is because Ice was on the surface. Ice in the form of glaciers and permafrost.

 

http://ancient-origins.net/news-history-archaeology/extensive-ancient-underground-network-discovered-scotland-turkey-00540