Many may remember “Rock of Ruck”. It was supposed to be Rocks of Ruck which would be dog talk for Lots of Luck. The jist was lots of luck looking for the rock that contained the cache. No longer a rock, I’ll say that much, or is it.
This is beside a paved walking trail in the city of Astoria between the trolly tracks and the Columbia river. This can be a very popular place in the summer so depending on the time of the year stealth may be needed.
I could tell you what your looking for but then that would just ruin it for you. I didn't have a small enough pencil to put in it so you will have to bring your own. Be sure to put it back in the same place you found it for the next person and watch out for muggles.