Designing new objects in the perspective of creating useful functionalities at the nanoscale has been the subject of intense research efforts during the last 20 years. Coordination nanoparticles (CNPs) emerged less than 10 years ago, opening new possibilities for the design of bistable molecule-based objects where magnetism may be controlled or tuned by an external perturbation (light irradiation, temperature change, magnetic field, etc.). Magnetic cyanide-bridged networks have been shown to possess the potential to be shaped as nanoparticles, leading to new functionalities. Light- and temperature-induced bistable nanoparticles were thus discovered. Luminescent CNPs were also prepared, demonstrating the large potential of these objects.