The invention discloses a method of forming nanostructure and nanostructure. A first block copolymer is provided. A substrate is provided having an energetically neutral surface layer with at least one trough integrally disposed thereon with sidewalls. A first film of the first block copolymer is formed inside the trough. Line-forming microdomains are assembled of the first block copolymer, and form first self-assembled structures within the first film normal to the sidewalls and parallel to the surface layer. At least one microdomain is removed from the first film such that oriented structures remain in the trough; wherein, the oriented structures are normal to the sidewalls and parallel to the surface layer. A second block copolymer is provided. A second film of a second block copolymeris formed inside the trough. Line-forming microdomains are assembled of the second block copolymer, and form second self-assembled structures within the second film oriented normal to the oriented structures and parallel to the sidewalls.