Stacking container, method and system

The application discloses a plurality of hexagonal interlocking containers 1. Each container comprises six faces 2, each face has an engagement portion (either in the shape of a groove 4 or a protrusion 3), and each portion has three faces. The engagement portions are designed such that they can be pulled apart radially but not laterally. The profile of the container may be such that protrusions and grooves have an alternative arrangement. The profile may be formed into the wall of the container. The length or the engagements portions may represent more than 10% of the length of the side wall. The container may comprise a recess in base such that protrusion located on the top surface of another container can fit inside the recess, such that the containers can stack. Preferably, the container may comprise a handle (28, figure 24) and second opening (6', figure 11). There are additional claims for 1) a plurality of containers being stack horizontally and individual containers being removed from the said stack, 2) a method of using the containers in as brick for construction purposes, 3) a bracket to be used in conjunction with the container and 4) a computer-implemented addressing system used to ID individual containers in a stack.