The sea has long been a source of enduring mystery and wonder. While satellite imagery now lets us pore over every inch of the Earth’s surface in detail, less than 5% of the world’s oceans have been explored. Couple that with recent leaps in underwater drone technology and the fact that changing climate patterns are beginning to alter coastlines around the globe and unearth (unsea?) long-forgotten pieces of human history as well as more modern maritime mysteries. Just this week, seaborne mystery lovers got a fresh dose of wonder when a mysterious ringed structure rose from the sands of a Canadian beach during low tide and triggered debate over what the curious structure might be.

The strange wooden ring was found on Prince Edward Island, one of Canada’s maritime provinces and oldest active settlements. Beachgoer Ellen MacLeod was strolling the shores near a harbour in Alberton, P.E.I. when she came across a semi-circle of deteriorated wooden posts protruding from the sands. MacLeod did what any member of modern society would do and immediately snapped pictures of the curious construction, posting them to the “Historic PEI” group on Facebook.

Prince Edward Islanders began chiming in on the social network to speculate what the structure might be. The most common answers ranged from an abandoned First Nations fishing weir to a forgotten breakwater. Some users stretched their imaginations further, guessing it might be the shipwreck of a Spanish galleon or one of the 74 ships lost in the deadly Yankee Gale of 1851.

MacLeod returned the next day with her daughters to investigate further and possibly excavate part of the structure, but their efforts were hampered by the incoming tide. MacLeod told the CBC that she sides with the camp which believes the structure is likely the remains of a shipwreck:

My first impression was of course it had to be a ship. That was the exciting part and we were hoping it was. I asked a local, he said it could have possibly been there since the 1870s. I’m leaning more towards it being a ship because that part has a little bit more mystery to it.

Local historians are still investigating, hoping to cross reference the location of the structure with historical records of coastal settlements. The chance remains, however, that this could be an important forgotten relic of seafaring history.