To get an idea of what the box would look like and what its capabilities would be, I first found a box of reasonable size. I found a great one with an old world map on the outside along with leather straps for the closure. This was found at TJ Maxx Homegoods, which is a great place to find such a thing. Another option would be World Market, but I was satisfied with the box from Home Goods.
Next I gathered the main components - LCD screen, keypad, switch and locking switch, Atmega328p-pu, etc. I put together a bareduino to use as the main brain.
Next up I measured everything out and put together a design in inkscape for the laser cutter. I cut a cardboard prototype at the wonderful Make Salt Lake makerspace and after some adjustments cut a version out of 1/5" birch veneer plywood.
Originally I wanted to make the door an iris that automatically opened, but deciding that was too difficult I added a second puzzle to the upper lid of the box. The design was taken from this instructable with some changes to fit the theme of my box. One circle is now an analog clock and another circle contains characters from the Deseret Alphabet, which ties into the local history where the box will be played.
After staining everything and getting it set into the box I set to work on the programming portion. So far I have the GPS and LCD up and running. There is more work to do on the GPS implementation and then I will begin programming the steps of the game.