Storage apparatus for grain (2) which, unrestricted at rest, has a stable floating surface, in which an inner surface of the wall (1) of the apparatus is substantially parallel to the sloping surface. A grain silo of the invention may include means for circulating grain therewithin, the means being capable of moving along a path (6) and transferring grain from one point (4) to another (5) along the path (thereby causing the grain naturally to adopt a configuration defined at 4' and 5').