As far as the frontier the Oder flows through a well-defined valley,.
Above, on the western side, and partly lying on the site of the old ramparts, is the residential quarter, consisting mainly of villas and commanding a fine prospect of the Oder valley.
Of these the Pregel, Weser and Ems belong entirely, and the Oder mostly, to the German empire.
Situated on the high road from Berlin to Silesia, and having an extensive system of water communication by means of the Oder and its canals to the Vistula and the Elbe, and being an important railway centre, it has a lively export trade, which is further fostered by its three annual fairs, held respectively at Reminiscere (the second Sunday in Lent), St Margaret's day and at Martinmas.
In 1379 it received from King Sigismund, then margrave of Brandenburg, the right to free navigation of the Oder; and from 1368 to about 1450 it belonged to the Hanseatic League.