Archaeologists have found what looks like a Medieval board game inside the private bedroom of a 13th - century fortress closemouthed to the Russian - Finnish molding . According toa societal media postfrom Vladimir Tsoi , director of the Vyborg Museum - Reserve , it might just be the " most challenging " discovery since archaeologists began excavations in and around the rook sooner this year .

The   fortress is Vyborg Castle , located on a teeny tiny island overlooking the township of Vyborg in   Leningrad Oblast in northwestern Russia . It was build up by the Swedes in   1293 CE but its roots may be older still   – possibly to an earlier Karelian garrison , Newsweekreports .

In the intervening years , it has passed hands several times between Russia and Finland , most recently in 1944 when it was taken back by the Soviet Union .

The target itself is   basic   – a clay tablet with markings of intersecting square   – but expert believe it is an old variant of a two - musician strategy game calledNine Men ’s Morris , which has exist in some embodiment or another for century . Copies have been found everywhere from the UK to China to the Roman Empire and today you may know it as Cowboy ’s Checkers .

The intent of the plot is to beguile your opponent ’s pieces or " humans " . To do this , you must build up " manufactory " or rows of three men and for every grind you build , you take in one " man " . The winner is declared when their opponent is ineffective to build up any more mills   – ie they are left with only two valet .

In the stock game , each player starts with nine serviceman but depending on the version , it could be a few as three or as high as 12 .

Intriguingly , the game was found inside an underground chamber that may offer a secret passage to the town of Vyborg , at least if historical documents are to be believe . grant toVyborg Museum - Reserve , castle phonograph record dating back to the mid-16th century   mention a so - called   " private house " that direct to the shore of the strait . But for now , the grounds that it makes it as far as the shore stay inconclusive .

The board secret plan is not the first treasure   found within the castle walls .   This summer , archaeologists unearthed a aggregation of copper coins date stamp back to the former 19th 100 , Gizmodoreports .

[ H / T : Vyborg Museum - Reserve , Newsweek , Gizmodo ]