Hideouts for Super Villains

[Spikeo]

I think you've got it! There are some great ideas here (though the mobile subway base and the operational prison take the cake).

 

[Threedub]

Bad Dude Hideouts

Three non-common ones I've used:

Ocean Floor complex
Parallel Universe
Off-World Base through teleportation

 

[Shades of Green]

A few ideas:

1) An abandoned missile silo (or not so abandoned if you want a villain with nukes).
2) A moonbase.
3) Antarctic research facility.
4) A bomb-shelter complex left over from the Cold War.
5) A deep mine (abandoned or not - maybe the villain owns the mine and uses it to generate revenue?),
6) A submarine (nuclear, preferrably).
7) An ancient mansion or castle.
8) A graveyard (great for creating Zombie Plagues).
9) A government office (the villain has infiltrated a high position within the state-machine).
10) An abandoned hospital.

 

[Keeper of Secrets]

One option I had a long time ago was a villain who infiltrated my world's version of Arkham Asylum and was training and allying himself with some of the inmates. That made for a tough stronghold to attack.

 

[Graf]

Love the traveling subway idea; would be logistically complex but very challenging for the pcs.