We’re full of holes – crevice caves, caverns, potholes, sea caves, overhanging cliffs and grottos. The Niagara Escarpment is site to all the drama. During the last ice age, about 7,000 years ago, powerful waves pounded holes into the escarpment’s limestone walls. Today’s fascinating collection of caves includes tunnels and hourglass-shaped pillars. For the spelunker in you, these geological spectacles are natural funhouses. Sturdy shoes are a must.