Where incompetent (or out-of-favor) managers get sent, often as a prelude to getting sacked.  (Though not always). 

It's a common pattern (AntiPattern?) in industry when an upper-level manager is relieved of his/her duties (for poor performance or issues with the boss; see below), rather than being terminated directly he/she is assigned to run one or more "special projects"--some minor project activity usually of low importance to the company (otherwise the project would have a higher profile and not be given the label "special project"--it would be a full-fledged project on its own).  The assignment can serve several purposes:

* Gives the company time to decide what to do with the manager.  Another department may take the manager in to fill an opening.  (especially if the manager lost his/her previous post due to a conflict with his/her boss, rather than due to performance issues).  If no takers, then the manager gets the boot.

* Provide a subtle hint to the employee that his opportunities for further advancement with the company are limited, and that if he/she wants to ClimbTheCorporateLadder he/she needs to do so elsewhere.  (See UpOrOut)

* Humiliate the manager in order to encourage her/her to resign voluntarily (rather than firing him/her and having to pay a settlement package). ''This one can expose you to a constructive dismissal suit in the UK''

* Give the manager one last chance to redeem themselves--if they successfully manage the special project (not always easy, given the low priority afforded to such projects) they might be given more responsibilities.  Otherwise, HastaLaVista.  

Note that managers/employees who commit acts of misconduct generally aren't sent to the SpecialProjectsDungeon; they are just canned outright.

''There was some war movie where the group had to shape up or be put in the Leper''''''Colony.  It had planes and bombs.  It ties in with the bullet point about One Last Chance.  Help me remember?''