Those tiny black caches with the screwtop lid, hid on a piece of artillary at the post office... on the bottom of a bench at the park... on a signpost, a fence, a gate... That little log all rolled up and stuffed in it's little cacoon.
We love them - we hate them. Ok, we mostly hate them. 
Here is the sister cache to my most popular custom cache in PA. Let me first say, like any nano, it is magnetic. This one on a steel bridge! And like any difficult nano hide, it is not visible but will be located by touch. (yeah that's right - you can hate me now). The coords are good but you won't get much reception once you are under the bridge... so, figure out where to look before you leap. Finally, if you know me there's a twist of bee.