The Rupes Nigra ("Black Rock"), a phantom island, was believed to be a black rock located at the

North Magnetic Pole The north magnetic pole, also known as the magnetic north pole, is a point on the surface of Earth's Northern Hemisphere at which the Earth's magnetic field, planet's magnetic field points vertically downward (in other words, if a magnetic comp ...

or at the geographic

North Pole The North Pole, also known as the Geographic North Pole or Terrestrial North Pole, is the point in the Northern Hemisphere where the Earth's rotation, Earth's axis of rotation meets its surface. It is called the True North Pole to distingu ...

itself. Described by

Gerardus Mercator Gerardus Mercator (; 5 March 1512 – 2 December 1594) was a Flemish people, Flemish geographer, cosmographer and Cartography, cartographer. He is most renowned for creating the Mercator 1569 world map, 1569 world map based on a new Mercator pr ...

as 33 French miles in size, it provided a supposed explanation for why all compasses point to this location. The idea came from a lost work titled '' Inventio Fortunata'', and the island featured on maps from the sixteenth and seventeenth centuries, including those of Mercator and his successors. Mercator described the island in a 1577 letter to

John Dee John Dee (13 July 1527 – 1608 or 1609) was an English mathematician, astronomer, teacher, astrologer, occultist, and alchemist. He was the court astronomer for, and advisor to, Elizabeth I, and spent much of his time on alchemy, divination, ...

References

Phantom islands of the Arctic Ocean Islands of the Arctic Ocean North Pole {{geography-journal-stub