Earth actually has two North Poles. One is the magnetic pole, where the compass needles point. The other is the pole that the Earth's meridians cross.
The Earth rotates on the geographic north and south poles. The geographic north and south poles are where lines of longitude (meridians) converge in the north. The south and north pole are directly opposite to one another.
The North Pole is located in the middle of the Arctic Ocean. Scientists have tried marking the North pole. Because the water here is permanently covered with moving sea ice, it's practically impossible to construct any type of permanent station at the true North Pole.
On the other side of the Earth, the South Pole lies on a continental landmass known as Antarctica. Because the ice on top of Antarctica moves only a few meters a year, the United States Antarctica program has installed a marker here to delineate the true South Pole.