Cardboard cutout of the Perito Moreno glacier cave standing 90x47 inches. Most of these caves form from water naturally flowing under the glacier. Some are formed from volcanic heat. Some are unstable and highly prone to collapse. Image used is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license. We give appropriate credit to wikipedia user Martin St-Amant, provide a link to the license, and indicate that image distortions were applied to turn into a cardboard cutout. Licensor does not endorse us or our use. https://creativecommons.org/licenses/by-sa/3.0/deed.en
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