'Salt pits' in the Bible

Therefore, I live, An affirmation of Jehovah of Hosts, God of Israel, Surely, Moab is as Sodom, And the sons of Ammon as Gomorrah, An overrunning of nettles and salt-pits, And a desolation -- unto the age. A residue of My people do seize them, And a remnant of My nation inherit them.