An underground base is a subterranean facility used for military or scientific purposes.

Examples are:

There may be more than 10,000 underground military facilities worldwide.[1]

See also

edit

References

edit
  1. ^ Richelson, Jeffrey T. "U.S. Intelligence: Hiding of Military Assets by "Rogue Nations" and Other States a Major Security Challenge for 21st Century". gwu.edu. George Washington University. Retrieved 16 July 2020.