Chemical vapour deposition was used to grow a hard and simultaneously tough TiAlN nanostructure with six levels of hierachy. By using two variants of gaseous precursors, an irregularly arranged hard and tough multilayer stack was deposited, consisting of hard sublayers with herringbone micrograins, separated by tough interlayers with spherical nanograins. Micro- and nanomechanical testing indicated intrinsic toughening mechanisms mediated by five types of length scale-specific interfaces, resulting in intergranular, transgranular and cleavage fracture modes with zigzag-like crack patterns at multiple levels of hierarchy.