By Mara from Seattle, WA
A question mark indicates an "unknown" cache--what that usually means is there is some sort of puzzle involved that you must solve in order to get the coordinates. They have a very devoted following--some puzzles are amazingly complex, others relatively simple. People get hooked on the puzzles!
If you are in Seattle, you ought to visit Groundspeak HQ; they are the founders of the geocaching.com website, and people make visits to Seattle just to go there!
Our family has been geocaching nearly ten years; it is a great activity!
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