Potsdam's draw is its extraordinary concentration of royal architecture and parkland. The palaces and gardens on the western edge of the city are a UNESCO World Heritage Site — not a single monument but a whole landscape of interconnected parks stretching across several square kilometres. Allow at least a full day to scratch the surface, two to do it justice.
Away from the parks, the old town has its own pleasures: the Dutch Quarter and the Russian colony are unlike anything else in Germany, and the Cecilienhof is where post-war Europe was shaped.