Everyone hikes to the Grotto. It's the most popular attraction in Bruce Peninsula National Park. A big cave on the shore, it was carved out by the waves of Georgian Bay over thousands of years. From the Bruce Trail climb down through the natural chimney in the rock of the Niagara Escarpment. It's a pristine setting; there are no signs, lights, stairs or handrails here. The cave itself is stunning, with sunlight from the outside revealing a brilliant underwater tunnel on the inside. You can walk along a ledge inside its cavity or swim in its cool, clear, turquoise water.