这座古老的城堡矗立在城市中心，保护着居民免受外敌入侵。

The ancient ___citadel in the city center protected its inhabitants from invaders.

这座古老的城堡曾是村民们在战乱时的避难所。

The ancient ___citadel served as a refuge for villagers during the war.

家人的爱是他心灵的坚固堡垒，给予他面对困难的力量。

His family's love was his inner ___citadel, giving him strength to face difficulties.