Some parts of this chaotic area have not collapsed completely—they are still formed into large mesas, so they may still contain water ice. Chaotic terrain occurs in numerous locations on Mars, and always gives the strong impression that something abruptly disturbed the ground. Chaos regions formed long ago.
Certain areas within this chaotic region haven't fully crumbled; they persist as large mesas, possibly harboring frozen water.  Mars exhibits widespread chaotic terrain, each instance hinting at an abrupt disruption of the landscape. These formations are ancient in origin.