Five Islands is a site to be seen, a beautiful Nova Scotian destination where the sublime Bay of Fundy is the star of the show. For this annual event—eight years and counting—your race route is the bottom of the Bay itself. Yup, you’ll be running on the ocean floor, racing the highest tides in the world. There are both five- and 10-kilometre options for this picturesque feat of strength, both equally as stunning. At the finish line you’ll find yourself with a mucky pair of sneakers and new appreciation for Mother Nature.—Allison Saunders