stronghold

A fortified place or a fortress.

A place of survival or refuge.

An area dominated or occupied by a special group or distinguished by a special quality.

A fastness; a fort; a fortified place; a place or position of security: often used figuratively, and formerly as two words.

A fastness; a fort or fortress; fortfield place; a place of security.

A fortress

A place of refuge, survival or domination by a particular group or idea

a strongly fortified defensive structure