For a neat night time cache you could make a multi with the first part having a remote control. To find the second part you would have to go to coords a couple yards off of the actual coords. when you hit a button on the control it lights up the cache. I tried to do this but I have no knowledge of building remote controled circuits so it didn't work. If someone else can figure it out send me an email, I would like to see how it is done.
Sobeboy58