That so many tunnels have survived after 12,000 years shows that the original network must have been enormous.
Stone Age man created a massive network of underground tunnels criss-crossing Europe from Scotland to Turkey, a new book on the ancient superhighways has claimed.
German archaeologist Dr Heinrich Kusch said evidence of the tunnels has been found under hundreds of Neolithic settlements all over the continent.
The book notes that chapels were often built by the entrances perhaps because the Church were afraid of the heathen legacy the tunnels might have represented, and wanted to negate their influence.
In some cases writings have been discovered referring to the tunnels seen as a gateway to the