Subterranea (geography) explained

Subterranea are underground structures, both natural (such as caves) and human-made (such as mines).[1]

Some subterranea and related topics include:

Natural

Human-made or related

See also

Notes and References

  1. Margineanu . Romul Mircea . 2019 . Radon measurements in underground mines and caves from several European countries . AIP Conference Proceedings . 2076 . 050004 . Author(s) . 10.1063/1.5091643. free .