Geography and urban development of Dresden past 60 years has made Dresden the fourth largest urban area in Germany after Berlin, Hamburg, and Cologne. The most important river in Dresden is the Elbe river, the only navigable body of water to flow through the city. There are also a number of tributaries such as the river Weißeritz. The nearest German cities are Chemnitz (80 km to the southwest), Leipzig (100 km to the northwest) and Berlin (200 km to the north). The Czech capital Prague is about 150 km to the south; the Polish city of Wrocław is about 200 km to the east. There are
Accession of Hamburg to the German Customs Union (Zollverein) would remain undisturbed, as would the population, if they kept quiet. Otherwise, 10,000 Prussian troops would occupy the city. Wolffson and Halben reported this to Syndicus Carl Merck, who directed Hamburg's foreign affairs, who now sent Krüger, then in Hamburg, to Richthofen to obtain certainty about the Prussian threats. Merck addressed the Senate on 25 June saying he regarded the policy of Lübeck, which was positive to the Prussian alliance and the threats of Richthofen as particularly serious considerations. He was afraid that, after the accession of all other north German states to the alliance, Hamburg would stand isolated and