 The simplest honeycombs to build are formed from stacked layers or "slabs" of prisms based on some tessellations of the plane.In particular, for every parallelepiped, copies can fill space, with the cubic honeycomb being special because it is the only "regular" honeycomb in ordinary (Euclidean) space.Another interesting family is the Hill tetrahedra and their generalizations, which can also tile the space.