>>7743064https://www.ancient-origins.net/news-history-archaeology/extensive-ancient-underground-networks-discovered-throughout-europe-00540German archaeologist Dr Heinrich Kusch, in his book ‘ Secrets of the Underground Door to an Ancient World ’ (Original title in German: "Tore zur Unterwelt: Das Geheimnis der unterirdischen Gänge aus uralter Zeit ...") revealed that tunnels were dug under literally hundreds of Neolithic settlements all over Europe and the fact that so many tunnels have survived 12,000 years indicates that the original networks must have been huge.
