For most of its recent history Potsdam has not been accessible from Berlin. The last station before the former GDR was Wannsee. Many of the buildings that are visible today have been reconstructed after the bombings of the Second World War and after the lax care of the East German Government. The city as we see it today is the work of five architects (After the Great Elector had said: ''"Das ganze Eyland muß ein Paradies werden"'' (The whole island must become a paradise)): Peter Joseph Lenné, Georg Wenzeslaus von Knobelsdorff, Carl Phillipp Christian von Gontard, Karl Friedrich Schinkel and Friedrich Ludwig Persius, and of course Emperors Frederick the Great and Wilhelm II.It is important to realise that most of the tourist attraction in the city are UNESCO World Heritage sites - these are:*Sanssouci Park and the Crown estate of Bornstedt*The New Garden (including the Pfingstberg and the Russian colony of Alxandrowka)*Babelsberg Park*Sacrow Park http://wikitravel.org/en/Potsdam