The treasure of the Knights Templar is a case in point. Not the one they left for Dan Brown to find out; the one *they* dug out by apparent accident, which we now call money multiplier. I have no idea what name they had for the thing, nor if they were even conscious they got hold of a treasure in the form of actual, physical, solid gold coins. 

The jungle puzzle that guarded it consisted in the smooth operation of a consortium spanning the entire rigmarole of intercontinental tourism: from cruising companies to (crucially) currency exchange, via hostelry, private security, health care, corporate accounting and what else; yet no less crucially, excluding telefax services. Also including the required military gymnastics to  keep it in <i>uninterrupted</i> operation for more than 200yrs. 

The Order of the Knights Templar (OoKT for short) is known to have <a href="https://en.wikipedia.org/wiki/Promissory_note#History">issued promissory notes</a> against deposits in cash minus brokerage fees. Overtly or not, these notes were managed as <a href="https://en.wikipedia.org/wiki/Maturity_(finance)">maturities</a>. If  covertly, that is, if no maturity date was mentioned on the note, one would be implied if they were only payable in a designated town: the implicit date being set by the duration of the physical trip the note had to live thru, to reach its point of payment. Hence the importance of barring the average pilgrim or colonist access to fax, or rather to the <a href="https://en.wikipedia.org/wiki/Courier#Anabasii">nearest 13th C. approximant. </a>. 

The consequence is, the OoKT must have soon noticed each of its exchange offices was squatting on a heap of gold of roughly constant thickness and computed that, at whatever office it showed an inclination to dwindle, this would be linked with an increased popularity of the town among tourists. Hence, the dwindling could be controlled by writing an explicit maturity date on the notes; e. g. under the pretext that secure gold transfer to that specific office is slower if every ship heading to it is full to the rim with passengers of unknown probity. 

The next thing any banker in the OoKT's shoes would take notice of is, if each and every gold mattress entrusted to them has constant height over time, then  gold transfer is not needed at all: so, transfer authenticated balance sheets instead (those <i>are</i> needed, to beacon the managers of the exchange offices to the path of righteous poverty), which can be secured at much lower cost. The provision for hijacked or lost ships thus dropping by 90%, the broker can now pocket an equal portion of the exchange fees, and make a cosy income of what was originally a minimal indemnity against the risks in his business. This however is not the actual treasure; merely the tip for the clerk at the teller. 

The 3rd thing is to secure said mattresses against robbers, which as any banker will soon reflect, easily obtains by converting them to something several times heavier than a robber; to wit, <a href="https://en.wikipedia.org/wiki/Mortgage_note">real estate</a>. This is how bankers discovered <a href="https://en.wikipedia.org/wiki/Mississippi_Company">again and again</a> that, for better and often for worse, opening credit in excess of one's reserves amounts to creating actual, physical, 79Au money out of nowhere. This, in my view, is also how Philip the Fair discovered to his dismay that the actual, physical, 79Au-based wealth of the Order litterally flew up the chimney when <a href="https://en.wikipedia.org/wiki/Trials_of_the_Knights_Templar#Outcome">he sent them to the stake</a>.  

The OP only requires the jungle puzzle to <i>appear</i> as a deliberate setup authored by whoever buried the treasure, to select the worthy by intellectual challenge. Who did this in the case of the OoKT is anyone's guess; mine is, in long format, twas none other than Lil' Geez' o' Nazar'; witness, extant hints to the place of burial, <i>cf.</i> <a href="https://en.wikisource.org/wiki/Bible_(King_James)/Matthew#Chapter_19">Matt. XIX:21;</a> "go and sell that thou hast, and give to the poor, and thou shalt have treasure in heaven: and come and follow me. " Which the founders of the OoKT diligently did; only they correctly reckoned that once the Kingdom of Heaven tranferred its capital from Beloved City Up There to earthly Jerusalem down here, its central bank would follow suit, and down with it would the promised treasure. 

If this seems far-fetched, try Pope Gregory as the treasure-burier. He  advocated the Jews be <a href="http://www.newadvent.org/cathen/06780a.htm">left free to mind their business</a>; which traditionally includes pawnbroking and other financial services. So there might be a 1.3kyr old note describing the benefits of fractional reserve policy, somewhere in the Vatican secret archives. 
In short format, I don't have a clue, so your pet theory is welcome. Preferably backed with actual archives, secret or not; unlike mine.