'Fortified Cities' in the Bible

Announce ye in Judah, and cause to be heard in Jerusalem; and say, Strike the trumpet in the land: call, fill up, and say, Be ye gathered together and we will go to the fortified cities.

And it ate thy harvest and thy bread, that thy sons and thy daughters shall eat: it shall eat thy sheep and thine oxen: it shall eat thy vine and thy fig-trees: it shall break down thy fortified cities which thou trustedst in them, with the sword.

For what are we sitting? gather ye together and we will go into the fortified cities, and we shall be silent there: for Jehovah our God caused us to cease, and he will give us to drink the water of poison, for we sinned against Jehovah.

And the strength of the king of Babel warred against Jerusalem, and against all the cities of Judah being left against Lachish, and against Azekah: for these remained of the cities of Judah, fortified cities.