A method of forming a discrete nanostructured element at one or more predetermined locations on a substrate is presented. The method includes forming a mask member over the substrate. A window is formed in the mask member at each of one or more locations at which it is required to form the nanostructured element thereby to expose a portion of a surface of the substrate. A portion of the substrate exposed by the window at the one or more locations is removed to form one or more recesses in the substrate. The method further includes forming a layer of a nanostructure medium over a surface of the recess and annealing the structure thereby to form the nanostructured element in each of the one or more recesses. The nanostructured element includes a portion of the nanostructure medium and has an external dimension along at least two substantially orthogonal directions of less than substantially 100 nm.