The spell Secret Chest says this:
You hide a chest, and all its contents, on the Ethereal Plane.
So, my question is: Where in the Ethereal Plane does the chest go?
Along the same lines, depending on the answer to that, is it possible for someone to travel through the ethereal plane to find a secret chest? I'm asking about this part as well because depending on where it's hidden, it may be either easier or harder for someone to track down a secret chest.