It is a letterbox cache, which is at the stated coordinates. Please ensure that the stamp stays within the cache box.
If you wish, you may think up your own geocaching challenge and explain what its requirements are. Then explain in your log how you have met your challenge. "geocaching.com" caches and TBs etc only please.
Indeed, feel free to publish any self-challenge as a write-note, and come find the cache when you have achieved it.
You are completely free to just turn up and log the cache by itself.
Good hunting. You may also be interested in my other caches.