'Strongholds' in the Bible

Therefore, I will bring the worst of the [Gentile] nations, and they will take possession of their houses [those of the people of Judah]; I will also silence their pride, and their holy places will be profaned.

He devastated their strongholdsand destroyed their cities.The land and everything in it shudderedat the sound of his roaring.

And they put him in a cage with nose-rings, and brought him to the king of Babylon; they brought him into strongholds, that his voice should no more be heard upon the mountains of Israel.

“Tell them this: This is what the Lord God says: As surely as I live, those who are in the ruins will fall by the sword, those in the open field I have given to wild animals to be devoured, and those in the strongholds and caves will die by plague.