We visualize the conformational changes of paramagnetic particle chains at a one-dimensional interface. By tuning the strength of the external magnetic field, we changed the stiffness of the particle chains and their conformations at the interface. It is found that in the absence of an external magnetic field the particle chains easily undergo conformational changes, while in stronger fields they tend to keep their chain shape. In fields of intermediate strength, adsorption at the interface transforms the chains into stable pyramids.