This video illustrates an experimental study of the electrical transport behaviour of atomic-size contacts and mono-atomic chains of the nonmagnetic metal platinum. The development of atomic-scale structures revealing novel transport phenomena is a major goal of nanotechnology. Examples include chains of atoms that form while stretching a transition metal contact and the formation of magnetic order in these chains, the existence of which is still under debate. Here we illustrate an experimental study of the electrical transport behaviour of atomic-size contacts and mono-atomic chains of the nonmagnetic metal platinum. We find a pronounced and diverse magneto-conductance behaviour that sensitively reacts to tiny changes of the atomic configuration. Technically this is done by stretching a free standing nanobridge of platinum with subatomic precision. These findings can be interpreted as a signature of local magnetic order in the chain, which may be of particular importance for the application of atomic-sized contacts in spintronic devices of the smallest possible size.