Over 2000 years ago, on the Greek Island of Magnesia, rocks were found that attracted bits of iron ore.  These rocks were made of the mineral Magnetite, which is a magnetized iron oxide, Fe3O4.  [Each molecule of magnetite has three atoms of iron (Fe) and four of Oxygen (O).]

In the 1100's, the Chinese, who had also found this kind of rock, realized that this rock, if place on something that would allow it to spin freely, would always rotate to point in the same direction.  The part of the rock that pointed North was called the "North-seeking pole", or simply the "North Pole".  This was the first compass, and it helped lead them from place to place; we get the word "lodestone" from the old English for "lead" plus "stone".