You can drive around an area you’re interested in, or look at satellite or aerial photos, to find these facilities. “Security by obscurity” is no more useful here than it is in software systems.

You can also just randomly nuke a country or invade it for its resources.

Or poison the internet with AI generated garbage.

There are many alternatives to acting nefariously, this is just one.

Security by obscurity is actually useful, to some degree.