Frankfurt am Main (Frankfurt on the Main) refers to the river which flows through the city and also explains the frequently used expression "Mainhatten".The Main embankment has seen a great revival over the past decade: several cafes and bars opened, especially on the Sachsenhausen side. You can enjoy a very nice walk along the river, followed by a cold applewine in a deck chair with a fantastic view over Frankfurt's skyline.Historically and politically speaking, the Main forms the northern border of southern Germany and, with a length of 527 km is the longest right tributary of the Rhine; from its mouth in Mainz it is navigable all the way to Bamberg and since 1992 is connected to the Danube via a canal.Eight bridges cross the Main in Frankfurt, two of which, the 1868 built Eiserner Steg ("Iron bridge") and the more modern Holbeinsteg are for pedestrians only. Historically seen, the most important bridge is the Alte Brücke ("Old Bridge") - probably built in the 11th century - which until mid 19th century was the only stone bridge in the area connecting the Altstadt with Sachsenhausen. In the last couple of decades some new bridges were built: the Flösserbrücke and very recently, to serve commuters to the new European Central Bank offices, the Osthafenbrücke, which opened in Dezember 2013.