https://en.wikipedia.org/wiki/Camouflet
> A camouflet, in military science, is an artificial cavern created by an explosion; if the resulting structure is open to the surface it is called a crater.[1]
https://en.wikipedia.org/wiki/Camouflet
> A camouflet, in military science, is an artificial cavern created by an explosion; if the resulting structure is open to the surface it is called a crater.[1]