The electronic magnetic moment, and hence the atomic magnetic moment emerges from the combination of special relativity with quantum mechanics. In the solid state these individual magnetic moments may cooperate to generate a wide variety of macroscopic magnetic states. Some of these states shed light on the fundamentals of quantum mechanics; others find uses ranging from magnetic memory to fridges. In this talk, I will illustrate how such materials can be identified and investigated, focussing on neutron scattering techniques.