Why is North Always At the Top on a Map?

North doesn’t always mean “up” when it comes to geophysics. Scientists have known for decades that magnetic north, a spot once located in Arctic Canada, is moving toward Siberia. And magnetic north is different from geographic north, a place where all the meridians of longitude intersect in the Northern Hemisphere. But even these facts don't quite explain why modern maps always feature north at the top.

There’s nothing inherently upward about north. Some ancient Egyptian maps put south on top; in medieval Europe, Christian cartographers tended to give that distinction to east, since you had to turn that way to face Jerusalem. Others placed east on top because of the rising sun (that’s why we “orient” ourselves). And early American settlers sometimes used maps with west on top, because that was the direction they often traveled.

If anyone is responsible for maps’ northward focus, it’s Claudius Ptolemy. His Geographia, written in the 2nd century CE, featured a map of the known world with north on top. Why he positioned it that way is not clear, but it may be that the Library of Alexandria, where he did his research, just didn’t have much information on the Southern Hemisphere. Renaissance scholars revived Ptolemy’s work, and by then, the phenomenon of magnetic north had been discovered, making his layout even more appealing to mapmakers.

The magnetic north pole, however, was not located until 1831. On an otherwise disastrous expedition to Arctic in search of the Northwest Passage, British explorer James Clark Ross discovered the pole—the spot where a compass needle on a horizontal axis points straight down—on the west coast of Canada's Boothia peninsula. "I must leave it to others to imagine the elation of mind with which we found ourselves now at length arrived at this great object of our ambition," Ross wrote. "Nothing now remained for us but to return home and be happy for the rest of our days."

Discover More Maps:

A version of this story was published in 2014; it has been updated for 2025.