Tunnels - Detecting the Rabbit Holes
Interesting article on how to detect tunnel entrances in both urban and rural environments
Rabbit holes
The covert underground infrastructure serves many functions. Among these are strategic storage of materials and weapons, clandestine research and production facilities, alternant basing for military personnel and equipment, surface environment control systems (atmospheric lensing, synthetic earthquakes, weather modification, civilian population control, etc.), and of course sheltering essential government personnel during time of national crisis or war. This list is not complete, it is only indicative of the diverse ways in which the underground infrastructure is utilized.
It should be obvious that many of the uses listed above require both support from, and easy access to, the surrounding surface communities. I call these underground access points "rabbit holes", and they represent a key detectable feature of the underground infrastructure.
It should also be obvious that many of these uses require the facilities to be interconnected by a network of tunnels. The construction of these tunnels creates surface evidence of their existence, albeit transitory.
Rural Example:
-
The presence of inappropriate or unusual structures and/or construction methods. Examples: small cinder block building with an electrical power feed normally used on major office buildings. An unmarked, but well maintained trail in public park. An old building (possibly abandoned) with a new door, and expensive lock.
https://www.bibliotecapleyades.net/sociopolitica/sociopol_blackbudget02.htm