Hello TT Art treasures can be a very lucrative form of treasure hunting.
Amy
Yes Amy,,,I have also interest in that front,,some months back we were discussing about a possible find of such treasures with Crow and he posted several lost paintings that you can be rewarded if you give info about there whereabouts (of course some were stolen),,,I suggested at the time based on some amazing stories that it is good to now and then check flea markets of obscure towns in Europe and buy some old strange looking paintings for very cheap,,,who knows you may be lucky....but Crow pointed that even if one gets such valuable arts from flea markets by chance, you need to show the history of it's provenance as it might be stolen and you will have to hand it over,,,but some paintings have rewards attached to them so one can benefit from the rewards at least,, hence yes it is a good potential,,,so next time you pass an obscure town just check some old antique shop or flea market...

,,,,,I say old obscure towns because in bigger cities people are knowledgeable in such matters hence rare to find such valuables out in flea markets,,,,another related treasure hunt one can search is the first editions of many English books which are commanding tens of thousands by book collectors and auction houses,,,hence again a best place would be old obscure towns,
Here is one list for lost paintings with potential rewards
https://en.m.wikipedia.org/wiki/List_of_stolen_paintings
For list of valuable books check this,,the book front is in your area of expertise as it is literature,,
http://www.theguardian.com/books/2006/jan/19/news
TT