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In northwestern Wisconsin, crowds of people flocked last month to trek on a frozen-over Lake Superior to reach dramatic ice caves accessible on foot for the first time in several years, courtesy of the long frigid winter. The ice caves on Superior’s shoreline are carved out of sandstone by waves from the lake and derive their name from the icy freeze in winter that makes them glisten with hoar frost, icicles and ice formations. Reachable in warm weather by boat, the caves are accessible in winter only by walking across ice when it is thick and stable enough. Text and photos by Reuters