The continental divide is a place where the waters flow in one direction to one ocean and in the other direction they flow to another ocean. This picture shows the continental divide in the United States. Rivers flow east to the Mississippi and the Atlantic Ocean, and west to the Pacific Ocean.

In South America, the Andes is the continental divide, sending waters east to the Amazon and the South Atlantic and west to the Pacific Oceans. In Australia the Great Dividing Range does the same thing, while on a smaller scale (and not exactly a continent!) the backbone of England - the Pennine Hills, also splits most of the rivers.