The creative geocache series, Maple Ridge Cryptex Caper is highlighted as an example of a very creative cache. Not only for their design and build of an actual cryptex, but also for the exceptional work down on the geocache listing page.
Building robots is fun, easy, and can be done by nearly anyone. Learn the fundamentals to get started, and end by building a telepresence robot using a microcontroller and sensors. (Hobbies To Try Diy)