I know someone with considerable net worth who converted a good chunk of it into buried treasure, some of which I understand he has literally buried in places,

I know someone with considerable net worth who converted a good chunk of it into buried treasure, some of which I understand he has literally buried in places, and some he has squirrelled away under the floorboards or similar. He put a fair bit of thought into: A) Not forgetting where it is B) it being highly unlikely anyone would ever stumble across it and C) Ensuring his heirs find out about it should anything ever happen to him. C) was the tricky part, as he’s a lawyer, and therefore doesn’t trust lawyers, and he’s of a generation where technical solutions don’t appeal, and is ultimately the point of risk for anyone trying this route - either you accept that it crosses the Styx with you, or you tell someone, and take the risk therein. His view on C is that if his kids aren’t smart enough to find it, as he’s apparently left plenty of clues, then that’s their problem, not his. Part of his reason for being obtuse is that apparently in the jurisdictions he has concealed his wealth, buried treasure is taxed far more lightly than inheritance, and he wants them to have reasonable ignorance and deniability.