a strong castle in or near a city, where people can shelter from danger, especially during a war

The town has a 14th century citadel overlooking the river. 镇上有座14世纪的城堡俯瞰着河面。

a powerful organization in which finding a job is difficult for someone who does not know people who work there

At the age of 32, she managed to enter one of the citadels of high fashion. 32岁时，她成功进入了一个有着强烈排外情结的高端时装设计圈。