According to the Learner’s Dictionary STRONGHOLD is:
1 : an area where most people have the same beliefs, values, etc.: an area dominated by a particular group
The area/district/state is a Republican stronghold.
2 : a protected place where the members of a military group stay and can defend themselves against attacks
The rebels retreated to their mountain stronghold.
3 : an area where a particular type of uncommon animal can still be found
The last stronghold of the endangered deer.
This is Massachusetts’ Statehouse, from the back. It shows the tunnel that runs beneath it, originally designed to allow traffic to pass unimpeded. It has been closed for years, not unlike most of the minds within. This is a stronghold … of exactly what, you are free to decide for yourself.