While walking in the Cairngorms, a path had muddy puddles one day, and was frozen the following day. Parts of the path were the mixture of ice, air and gravel pictured. The structures are noticeable, because they collapse when stood on. They are different to any normal frozen puddles, because they are not solid ice, nor are they a layer of ice with water or air beneath. The pictured piece measures about 65x65 mm.