castrum

例句：

1. 1. The castle was a symbol of the ruling family's power.
   这个城堡是统治家族权力的象征。
2. 2.The fortifications were designed to protect the city from invaders.
   这些防御工事是为了保护城市免受侵略者的攻击。
3. 3.The citadel was a place of refuge for those fleeing the war.
   这个要塞是那些逃离战争的人的避难所。