[investigateworld]

I know where there's a bunch of abandoned mines going mines into the earth. Would the contents therein be EMP proof without additional shielding?

[RFEngineer]

The point is that under an EMP you wouldn't need to put all your electronics at the bottom of a mine. THey'll probably be fine at home with a surge protector and lightning protection on any external antennas.

But the bottom of a mine would be safe from an EMP, too.........