citadel

Pháo đài, thành lũy

a large, strong building or group of buildings that is used as a military base and can be defended against attack

• the citadel

Collocations citadel of power · citadel of resistance

• The citadel was built to protect the city.

  Pháo đài được xây dựng để bảo vệ thành phố.

Trụ sở chính, pháo đài tinh thần

a place that is strongly defended or supported by a particular group of people, especially in politics or religion

• the citadel of something

Collocations citadel of democracy · citadel of knowledge

• The university is the citadel of learning in this country.

  Đại học là trung tâm kiến thức hàng đầu của đất nước này.