'Fenced Cities' in the Bible

And in the fourteenth year of king Hezekiah hath Sennacherib king of Asshur come up against all the fenced cities of Judah, and seizeth them,

Hast thou not heard from afar, it I made, From days of old that I formed it? Now I have brought it in, And it becometh a desolation, Ruinous heaps are fenced cities,