La Brea Tar Pits

A Facebook Friend recently mused with consternation that they couldn't understand how a zombie, which will tear a person apart with their claws and fangs, couldn't pull themselves out of a mud hole.  I immediately thought of the La Brea Tar Pits which trapped many a creature far more fearsome than a zombie.  Add some natural traps like these to your tabletop roleplaying setting.  Read more here!