Dresden architecture and numerous world-renowned museums and art collections, Dresden has been called "Elbflorenz" (Florence of the Elbe). The incorporation of neighbouring rural communities over the past 60 years has made Dresden the twelfth largest urban district by area in Germany after Berlin, Hamburg and Cologne. The nearest German cities are Chemnitz to the southwest, Leipzig to the northwest and Berlin to the north. Prague, Czech Republic is about to the south and to the east is the Polish city of Wrocław. Dresden is one of the greenest cities in all of Europe, with 63% of the city being green areas
Accession of Hamburg to the German Customs Union (Zollverein) form a wider more powerful entity. The states which joined fought vigorously against any impairment of their full sovereignty. Hence each member had a veto and the union was not permanent, but had to be renewed after 12 years. Each member sought its own economic advantage. Accordingly, the accession of any of the Hanseatic cities of Hamburg, Bremen or Lübeck would have to be on condition that accession served the city's own advantage. A pre-condition of such advantage was that their territory touched directly with that of the Customs Union, which only happened for Hamburg after 1854, when Hanover joined.