Many people visit Canada’s Prince Edward Island to live out literary childhood dreams. The island, after all, was the setting of the beloved Anne of Green Gables novels. But for those less inclined toward tracing the footsteps of the fictional Anne Shirley, the western end of the island offers a more down-to-earth experience. Or maybe that should be down-in-the-earth, as the town of O’Leary is the home of the Canadian Potato Museum. Open from mid-May to mid-October, the museum showcases the local potato industry and sports the “world’s largest exhibits of potato-related farm machinery,” along with the largest potato sculpture in the world. 

Of course, a potato museum requires a potato-themed cafe, in the form of the PEI Potato Country Kitchen. But despite the potato-bread grilled cheese and the potato fudge, one of the most popular menu items doesn’t involve potatoes at all. Instead, visitors devour the museum’s seaweed pie, made from the Irish moss that once fueled the island’s economy. 

In the 20th century, locals harvested huge amounts of Irish moss, Chondrus crispus, from the waters around Prince Edward Island, whether raking it from the shallows on horseback or gathering it from the beaches after storms. After all, Irish moss contains carrageenan, a thickening agent used in ice cream and toothpaste. But now, a diminished stock and cheaper Irish moss from around the world have shrunk the local industry. One survivor is the museum’s seaweed pie. 

Really, though, it’s more of a cake. Cream thickened with local Irish moss–derived carrageenan tops a base that resembles angel food cake, and it’s finished with a berry sauce of your choosing. As for why the Canadian Potato Museum serves it, they employ the baker for the now-closed Seaweed Pie Café and Irish Moss Interpretive Centre in nearby Miminegash, once the Irish moss capital of the world.