A 3-dimensional, upwardly convex frame (40) constructed from a plurality of substantially identical longitudinally extending frame members (42). The frame (40) includes: the frame members (42) connected at approximately their ends to above approximately the middle of adjacent frame members (42) and the frame members (42) connected at approximately their middle to below approximately the ends of adjacent frame members (42) in a generally outwardly extending sequence. The outwardly facing ends of the outermost frame members (42) are un-connected.
