citadel
//ˈsɪtədəl//
Noun
citadelSingular
citadelsPlural
1
A fortress, typically on high ground, protecting or dominating a city.
The ancient citadel stood on the hilltop, overlooking the entire city.
2
A strongly fortified building or place of safety; a stronghold.
The ancient citadel provided refuge for the villagers during the invasion.
3
A place or situation regarded as a center of defense or protection for a particular belief, principle, or group.
The university has long been a citadel of free speech and academic freedom.