The Oder is a river with the letter O. It is located in Europe, more precisely in the middle of the continent. It flows through Poland, the Czech Republic and Germany. It is the second longest river in Poland in terms of total length, which is over 854 kilometers.
One of the rivers located in Africa is the Okavango with the letter O. Its length is 1600 kilometers. Unlike most other rivers, it does not end its course in the sea, but in the Kalahari Basin, in a swampy reservoir. It runs through three countries named Namibia, Botswana and Angola.