At Stage One, you will find a camo'd pill container which contains a field puzzle to figure out. It can be done in the field, there is no need to remove the puzzle and take it home.
Once you have figured out the puzzle, you have the co-ordinates for the final which is about a km walk from stage one. You will be taken to another historical location, one of which, some of you have already been to, but it's too nice not to revisit.
Before you go off to the final, be sure to take a look at some of the historical plaques nearby, they contain a lot of great historical information and are well worth the read.
Have fun and happy caching!