Subterranea are underground structures, both natural (such as caves) and human-made (such as mines).[1] Some Subterraneaand related topics include:
Subterranea are underground structures, both natural (such as caves) and human-made (such as mines).[1] Some Subterraneaand related topics include:
Man-made and man-related Subterranea | |
|---|---|
| Natural features | |
| Civilian features |
|
| Military features | |
| Mining, quarrying, and underground construction | |
| Related topics |
|
| Earth shelters US | |
| Earth shelters UK | |
| Earth shelters Australia | |
| International | |
|---|---|
| National | |
