Perito Moreno Glacier, Argentina

The ice wall of the Perito Moreno Glacier looks mostly harmless from afar (as pictured in this photo) but there is a reason that boats won’t tread too closely to that massive wall, bobbing about 180ft above the water surface of Lago Argentino. Chunks break off and fall into the lake with resounding cracks and the painterly sky observes nonchalant from above, like the visitors who photograph.