The oblong rocks at the Eureka Springs Gardens in Arkansas, USA, bring a curious smile to passing tourists, once they inspect them closely. Grey and smooth, the rocks have a fabric imprint, resembling coarse canvas sacking. They look remarkably like sacks of flour! The bottom of one sack is elongated and even preserves a pattern of stitching. The top is pulled together, complete with petrified wrinkles, as if it was once tied with rope.