The Oder has its beginnings in the Czech Republic in the Oder Mountains, the easternmost part of the Sudetes. First it flows towards the north-east. Behind Ostrava, after crossing the border with Poland, it heads towards the north-west. It flows through Racibórz, Opole, Wrocław and approx. 8 km north-east from Zielona Góra, the Oder river starts to flow towards the west. At the border with Germany Nysa Łużycka falls into the Oder and from this point the river follows the border to the north, flowing through Frankfurt (Oder) and Kostrzyn (Oder). Then it flows towards the north-west and near Cedynia it changes directions again and flows towards the north-east through Gryfino and Szczecin. The river flows into the Oder Roztoka, one of the bays of the Szczecin Lagoon. 

The Oder is the second long river in Poland with a total length of 854.3 km. Regarding the length within Poland it is the third long river in Poland (742 km) after Vistula and Warta. According to the Water Law the Oder is shorter and it is only 840 km long. The act dated July 18, 2001 divided the surface waters into inland waters, territorial sea and internal sea waters. A bridge on the Zamkowa Trail in Szczecin constitutes a border between sea waters and inland waters. It means that from the legal point of view, when you walk along the Chrobrego embankments, you can see a sea, not a river.

The Zachodniopomorskie [West Pomerania] Province includes the lower course and the mouth of the Oder. It is an exceptionally valuable area in terms of nature. It has been protected within Natura 2000: Lower Oder and the Lower Oder Valley, as well as the Lower Oder Valley Landscape Park and Cedynia Landscape Park. On the German side a part of the valley is included in the Lower Oder Valley National Park (in German Unteres Odertal).

In the area the Oder created an interesting mosaic of habitats. On the floodplains there are mostly swamps, marshes, bogs and meadows. The most interesting area is Międzyodrze with numerous canals and islands. They constitute extremely important sanctuaries for wetland birds. In autumn there could be up to 9 000 gantries. It is possible to observe various species of birds, including great bittern, little bittern, common kingfisher, great egret, red kite, and white-tailed eagles. There are otters, beavers, moose and bats: barbastelle, greater mouse-eared bat and pond bats. It is therefore a perfect place to observe wild nature. Numerous viewpoints, including Gozdowice and Zatoń Dolna, will help with this.

The slopes and other non-floodplain area are covered with meadows with xerophytes (including xerothermic) and forests. It is related with a specific and warm as for this latitude climate of the Oder Valley, a small amount of precipitation and a large number of sunny days annually.  Flat moraine uplands were used for cultivation, while steep slopes were used for pasturing sheep and goats. It stopped the succession of forests and thanks to this the xerothermic accumulations were preserved. Today within active protection of some grasslands pasturing is applied again, therefore in summer one can come across flocks of sheep by the Oder. Large forests are attached to the Oder Valley: Puszcza Bukowa [Bukowa Primeval Forest], Puszcza Goleniowska [Goleniowska Primeval Forest], Puszcza Piaskowa [Piaskowa Primeval Forest] and Puszcza Wkrzańska [Wkrzeńska Primeval Forest].

The Oder constitutes one of the fisheries in Poland with the largest amount of fish. Fishing enthusiasts can catch asp, chub, ide, as well as zander, wels catfish and northern pike. Water sports enthusiasts can take advantage of the water trails and numerous havens. The Oder is regularized and there are kayaks, as well as sailboats and passenger ships. Every year in summer they organize Flis Odrzański, which involves rafting and sailing. It finishes in Szczecin with the celebrations of The Day of the Oder River. It is also worth visiting the Szczecin Harbour, where seagoing cruisers, river cruisers, as well as cargo ships call in.