'Citadel' in the Bible

The Lord has become like an enemy; he has destroyed Israel; he has destroyed all its citadel fortresses; he has ruined all its fortifications and multiplied lamentation and mourning in the daughter of Judah.

The Lord has rejected his altar; he has rejected his sanctuary; he has delivered into the hands of the enemy the walls of its citadel fortresses. They have cried out in the house of Yahweh like a day of an appointed feast.