Maine"s Acadia National Park serves up spectacular views at most every turn. But the park"s Otter Cliffs on Mount Desert Island offer the adventurous among us a chance to take in the picturesque Atlantic shoreline from the edge of a sheer granite wall. Rising some 60 feet above the crashing waves below, the cliffs are shown here at low tide—when the tide is up, that ledge at the bottom is completely submerged.