The Oder River is a river that forms part of the border between Poland and Germany. It is 434 miles long and flows from the Czech Republic to the Baltic Sea. The river's name in German is spelled 'Oder' and in Polish it is spelled 'Odra'. The Oder River is an important waterway for both countries, providing transportation, irrigation, and hydroelectric power. The river is also known for its strong smell, which is why it is sometimes referred to as the 'ODOR' River.