Ok here is the answer.

Imagine a circle around the earth which is of circumference 1 mile. There will be 2 such circles on the earth. One close to the north pole and one close to the south pole. Consider the one closer to the South pole.

Now take any point in this circle. From this place, go one mile north. Make this as your starting point. From here go one mile South and you will hit the circle mentioned earlier. Go one mile west from here and you will be back at the same point in the circle as the circle is of circumference one mile. Go one mile North and you are at the same point from where you started your journey.

Since there are infinitely many points in a circle, there are infinite answers to this puzzle.

Hope this justifies.