'Fortified Cities' in the Bible

Now it came to pass in the fourteenth year of king Hezekiah, that Sennacherib king of Assyria came up against all the fortified cities of Judah, and took them.

Hast thou not heard long ago, how I have done it; and of ancient times, that I have formed it? now have I brought it to pass, that thou shouldst be to lay waste fortified cities into ruinous heaps.