A vast, intricate design with microscopic details at hundreds of levels of emergent forms, coloured in semi-transparency generating holographic effects, using spectra of light far beyond the human visual range, executed in three dimensions and occupying hundreds of cubic miles. Oh, and why not animate it? It would have to be virtual I suppose, or vastly too expensive to ever be created physically. In fact, why design it to be physically possible? Go nuts, make it 7 dimensional.
