Structures are provided that have an enclosed interior space that can be used to hold and contain water or other matter. The interior space is defined by an enclosing wall and a base that are both waterproof to prevent leakage of the water or matter contained in the interior space. None, one or more frame members can be provided as part of the enclosing wall and the base, or a frame member can be provided as part of a rim member. The frame members can be foldable to allow the resulting structure to be twisted and folded to reduce the overall size of the structure.