I guess this is kinda childlike, to want to do something like this. But, releasing my inner child is only a good thing!
I don’t know what to define as my ‘treasure’.
Perhaps a time capsule, although to some it would be worthless, to others it would be treasured. Then make a map and guard it untill my death, at which time it would probably be dug up again by then.
Sounds like a plan, aye?