A common geographical myth is that only a few rivers flow north. In reality, rivers flow 'downhill' regardless of cardinal direction. In the United States, a tricky question often involves the Red River of the North, which flows north into Canada, or the St. Johns River in Florida, which also flows north. However, the most famous 'north-flowing' river in the world is the Nile. In the US, the New River is often cited as one of the few rivers that flow from south to north, and it is also considered one of the oldest rivers in the world, potentially predating the Appalachian Mountains themselves. These rivers remind us that topography, not magnetic poles, determines the path of water.