The northwest portion of Philadelphia is absolutely crammed with some stunning public parks. Clifford Park, just adjacent to the larger Wissahickon is a great hidden gem, that includes a baseball field, trails, streams, old Victoria/Edwardian architecture and probably one of the best sledding hills in the city.
All that aside, this cache involves a different kind of field, a magnetic one. I've wanted to make a cache that dealt with magnets for a while now as they're a low-tech way to add fun to a gadget. The stars have aligned at last and after clearing out some old baby proofing items and acquiring a 3d printer I was struck with inspiration for a fun gadget cache for all ages.
You’ll need a fairly common tool of the trade to unlock the secret of this cache, the stronger the better. I can’t be positive, or negative about the orientation of your tool, so one goes both ways (north and south) would be a safe bet. The wrong way around and you’ll end up just locking it even tighter. With your tool in hand you just need to pick a color and listen for the magic. Red or blue will open things for you, no need for both.
Enjoy!