'Fortified City' in the Bible

Now, therefore, when this letter cometh in unto you, there being, with you, the sons of your lord, - and, with you, the chariots and the homes, and a fortified city, and the armour,

And the sons of Israel did, secretly, things which were not right, against Yahweh their God, - and built for themselves high places in all their cities, from the watchmen's tower, to the fortified city.

He, smote the Philistines, as far as Gazah, and her boundaries, - from the watchmen's tower even to the fortified city.