I recently came across this question. It presents a conundrum that it claims to be as-of-yet unsolved by anyone.

Several people did a lot of work and research, and managed to come up with a reasonable, if not verifiable, solution to the puzzle.

It got me thinking: There are myriad famous unsolved puzzles out in the world, that have remained unsolved for years, decades, or even longer. For example:

Now, I don't expect that the patrons of Puzzling.SE are better than all the various experts that have tackled some of these puzzles over the years, but I also think that the users of this site might appreciate being exposed to some of these classic conundrums, if they have not already been.

Hence the question(s):

  • Is it appropriate to post famous unsolved puzzles on Puzzling.SE?
  • If so, what measures/precautions should be taken to ensure that solvers aren't frustrated by being unable to solve them?
    • I assume that it should be made very clear that these are as-of-yet unsolved, and that a solution is not necessarily expected. Are there other things that should be noted?
  • 1
    $\begingroup$ "I don't expect that the patrons of Puzzling.SE are better than all the various experts..." - don't be so sure! There are some damn clever people here :-) $\endgroup$ Commented Aug 28, 2015 at 19:01
  • $\begingroup$ Yes, look up @rep al'whor... damn clever person! $\endgroup$
    – d'alar'cop
    Commented Aug 28, 2015 at 21:15
  • $\begingroup$ +1 I've wondered about this too, in regards to en.wikipedia.org/wiki/Fenn_treasure it would be impressive, albeit awkward logistically, if we could figure that one out (assuming it's legit) $\endgroup$
    – NeedAName
    Commented Aug 29, 2015 at 4:09
  • $\begingroup$ puzzling.stackexchange.com/tags/real/info $\endgroup$
    – warspyking
    Commented Aug 30, 2015 at 15:52
  • $\begingroup$ @warspyking I would have gone with unsolved or unsolved-puzzle myself... $\endgroup$ Commented Aug 30, 2015 at 16:20
  • $\begingroup$ But it could be a real mystery that HAS been solved. Granted that may be rare, but possible. $\endgroup$
    – warspyking
    Commented Aug 30, 2015 at 16:58
  • $\begingroup$ @GentlePurpleRain - My answer is just my opinion. I would actually be interested to see the response if you put together a question. $\endgroup$
    – Len
    Commented Aug 31, 2015 at 4:30

3 Answers 3


I think just post them.

There aren't very many of them. And who can judge whether there's a reasonable chance of a solution?

A question on the Voynich manuscript here, for example, would attract people who are interested and who want to put their heads together, and could get a lot of very stimulating answers over a long period of time. That could only be a good thing.

Frustration? What's the problem? People who enjoy tackling hard puzzles can deal with it; they even enjoy dealing with it!

Create a tag.


I suggest that famous unsolved ciphers should only be posted if it is reasonable to expect a good answer from the Puzzling.se community. The same approach is taken on Math.se.

I think that Puzzling.se should not be a repository for ciphers that are very unlikely to be solved. As google shows, a lot of expertise has already been applied to the Kryptos, Beale, and Voynich ciphers. In addition, there is suspicion that the unsolved Beale ciphers and the Voynich manuscript are just fabrications with no meaningful solution.

Here is a list of 64 encrypted books (some have been solved) and another list of unsolved ciphers that includes shorter texts like the D'Agapeyeff cipher and the Feynman ciphers.

From these lists, perhaps Puzzling.se could solve the Penitentia Manuscript because:

  1. there is assurance of a real solution
  2. the author expects that it is solvable
  3. it appears that others have made minimal effort to solve this cipher (compared to the more famous ciphers)

I am interested in further discussion.

  • $\begingroup$ Please do post the Pentitentia Manuscript! It looks very interesting. $\endgroup$
    – Hackiisan
    Commented Sep 3, 2015 at 21:31

I would positively lose my mind over more of these real-life mysteries! They should definitely belong here. I had a total blast with the double edged sword and am actually back into Latin again as well as starting to get into learning Greek. Something on the Voynich manuscripts, I may be looking at it wrong but, some parts look as if they were stamped as oppsed to completely hand-written, unless what i was looking at was a re-rendered/reproduced example. Anyway, MORE yes please.

Edit: Not "modern" mysteries, they just seem plastic.

A quick thought, frustration is part of the trip, and a solution is not always guaranteed. That's why these mysteries are mysteries, if you're not willing to risk the anime-style death when you encounter a puzzle that can't be solved then where is the fun in that?


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