This is another classic puzzle which can be found in many different books – a highly recommended puzzle for your children to help them think n 3-dimensions and explain some special properties of a sphere.
How many points are there on the globe where, by walking one mile south, one mile east and one mile north, you reach the place you started?
Alok Goyal's Puzzles Page 
One? The North Pole.
Publishing your comment sooner than the end of the week as many people have responded with a similar answer. While North Pole is a correct answer, the real puzzle starts once you figure out the North Pole 🙂
Good one Alok. This is an infinitely beautiful puzzle. Little bit of a challenge to get kids thinking on this but the discovery in the end fascinates them …
agreed…BTW, I am seeing the same effect on adults 🙂
It certainly fascinated me as well. 🙂 At one point I wondered if going east, do you at the halfway point start going west, but soon realized that the definition of going east is probably increasing eastward or decreasing westward longitudes. Very nice one 🙂