Overrun place locked in Dead of winter?
When zombies overrun a location each zombie that overruns kills a survivor that is at the location. What the means is that even if all the places for zombies are filled you can still go back there to try and do something but unless you kill some zombies any that get added will kill the survivors at the location.

Rules


  Whenever adding zombies, they are added 1 at a time until
  all zombies that need to be added have been added.
  When adding zombies to the colony, always place the first
  zombie on any empty space in entrance 1, the second zombie
  on any empty space in entrance 2, the third zombie on any
  empty space in entrance 3, etc. until all of the zombies that
  need to be added have been placed. When adding a seventh
  zombie, place it on any empty space in entrance 1 again, an
  eighth zombie on any empty space in entrance 2, etc. If there
  are no empty entrance spaces in the entrance the zombie
  would be placed but there is a barricade token in one of
  those spaces, destroy that barricade token and remove the
  zombie that would have been placed. If there are no empty
  spaces and no barricade tokens, the entrance has been
  overrun, remove that zombie and kill the survivor at the
  colony that has the lowest influence value. If there are only
  helpless survivors at the colony, kill a helpless survivor. If
  there are no survivors at the colony remove the zombie that
  would have been placed without further effect. Every time a
  survivor is killed (including a helpless survivor), decrease
  morale by 1. When adding zombies to non-colony locations
  follow all of the same rules, except there is only 1 entrance to
  place zombies in so all of the zombies are placed in spaces at
  that entrance. See Example: Adding Zombies to right.
  In the rare case that players ever have to
  add zombies and there are no more zombie
  standees left, use the zombie tokens included
  in the game to add the additional zombies