stronghold
//ˈstrɒŋˌhəʊld//
Noun
strongholdSingular
strongholdsPlural
1
A place that has been fortified to protect it against attack; a fortress or castle.
The ancient stronghold stood on top of the hill, protecting the village below.
2
A place where a particular cause, belief, or group has strong support or is dominant.
This region has long been a stronghold of the conservative party.