For both fundamental research and technological applications it is of interest to understand and control the magnetization reversal and the pinning of domain walls in ferromagnetic nanostructures. The present work provides new insights into the magnetic behavior of electrochemically synthesized nanowires by applying established methods such as magnetoresistance measurements and magnetic force microscopy as well as a novel photoemission electron microscopy method developed at the synchrotron light source BESSY II in Berlin, Germany. A main focus lies on the feasability of domain wall preparation in cylindrical nanowires with one or more diameter modulations. Furthermore, domain nucleation and pinning of domain walls in flat Co/Pt multilayer wires with perpendicular magnetic anisotropy is studied by transmission x-ray microscopy.