Along the shores of Brittany, France, a mysterious stone sits at the edge of the tide. On its face are mysterious carvings, believed to have been made just over 200 years ago by an unknown author. From the Rosetta Stone to cuneiform texts, archaeologists are no strangers to weird engravings on solid objects. What has them confounded is that these carvings don’t resemble any known language.

A Maritime Mystery

Nestled along the coast of Plougastel-Daoulas in northwestern France lies a stone that is only visible during low tide. It has been a source of local interest since its rediscovery a few years ago, but no one who has looked at it so far has been able to understand the unusual markings etched into its surface. From what people have been able to tell, the “code” is a jumbled series of capital letters, some unknown symbols, a sailboat, a heart atop a cross, and the dates 1786 and 1787. According to a local town official, the years correlate to the installment of a series of artillery batteries and fortifications that were constructed to protect the nearby Fort du Corbeau. Recently, the town opened interpretation of the inscriptions to the public, offering a reward of just over $2,000 to whoever could decipher the inscription. Puzzlers and code-breakers are welcome to take a crack at the Brittany stone engraving until the end of November when a jury will meet and decide which interpretation is most likely correct. If the temptation of a riddle entices you, you may want to know a few things about Brittany and its history before you delve into deciphering the cryptogram.

French By Technicality

Brittany is located in the northeast of France’s hexagon and is bordered by the Celtic Sea to the west, the Bay of Biscay to the south, and the English Channel to the north. Historically, Brittany has retained more of its Celtic ancestry than the rest of France, which was once inherited by the Gauls. As a result, many of the names and elements of the dialect found in Brittany are distinctly different from their central counterparts. During the late 1700s, many Bretons crossed the Atlantic to aid in the American Revolutionary War. When they returned, the decade that followed would be strenuous as they led up to the beginning of the French Revolution in 1789. At the start of their revolution, Brittany lost many of its self-governing rights. Three years into the war, it became a hub for royalist and Catholic resistance against the uprising, and the region’s economy suffered throughout the 19th and into the 20th century. Before the 1800s, Brittany’s most pervasive language was Breton, which is a Celtic-influenced Indo-European language most closely resembling Cornish. Also relatively common was Gallo, which is a Romance-derived language. Nowadays, both languages are endangered, with Breton nearing extinction as fewer than half a million native speakers remain, the majority of them being over 60 years old.

Putting It All Together

With a bit of knowledge under our belts, the grounds for speculation grow immensely. Perhaps the stone is a memorial or honorary tribute to a love left behind in America during the war. Maybe they went back, or perhaps they were wed on that very spot. There is a chance that the stone is engraved in Breton, at least in part. The strange symbols could be a form of shorthand or another symbol-based alphabet. What we do know is that the only publicly deciphered sections of the stone are sequences of capital letters that read: “ROC AR B … DRE AR GRIO SE EVELOH AR VIRIONES BAOAVEL … R I OBBIIE: BRISBVILAR … FROIK … AL.” Most people seem to expect the stone to hold incredible secrets, but it could very well just be something as mundane as an old shopping list.