I love the escape room idea as another lesson plan type! I especially like the potential for small, multi-age workshops.  Younger children can look for items that are part of clues for older ones to figure out.

The link the Resource Droid has provided has a couple of "breakout box" ideas as well.  Our city library has a toy section as well as books and one of the items is an "Escape Room in a Box" (a "breakout box"), which we are going to borrow to get a better idea of how one works and how we might be able to adapt this for our purposes - hopefully photos to follow!