A map from 1805 show the fictional Mountains of the Moon bisecting the African continent. (Photo: Wikipedia)

The search for the source of the Nile captivated civilizations for centuries. For a long stretch of time from ancient Greece right up into the 19th century, the answer to that mysterious question was the Mountains of the Moon. This range of peaks wound up on a number of maps despite being entirely fictional.

While the Mountains of the Moon likely sprung from an ancient Arab idea, the legends survive mainly thanks to accounts by classical explorers and historians, namely Ptolemy. Ptolemy’s Geographia, written around 150 CE and adapted from an atlas by the geographer Marinus of Tyre, says the Mountains of the Moon were first discovered by a traveling merchant named Diogenes. He was crossing East Africa circa 110 CE when he accidentally stumbled upon the source of the Nile, emanating from snowmelt pouring off of what he called the “Moon Mountains.” From there the waters pooled in a pair of great lakes that fed the river.

It is now thought these lakes could have been what we know today as Lake Albert (located in Uganda) and Lake Victoria (which sprawls across Tanzania and Uganda), but in Ptolemy’s estimation, they lay much further south on the continent.   

In the second century CE, when Ptolemy was around, European expeditions to the interior of Africa had rarely been successful enough to create an accurate picture of the geography. Ptolemy’s account of the fabled mountains was therefore taken as gospel. With no other explanations for the life-giving Nile’s ultimate, inland origin, the Mountains of the Moon, as they were eventually called almost uniformly, continued to spread throughout the geographic and cartographic worlds. Even as more and more of the African interior began being accurately mapped, the Mountains of the Moon continued to appear in some form or another.

Kircher’s map of the Mountains of the Moon. (Photo: Fondo Antiguo de la Universidad/Flickr

In 1664, eccentric scholar Athanasius Kircher created one of the more whimsical maps of the mountains showing a giant lake hidden within the peaks. According to Kircher, the waters inside the Mountains of the Moon fed the Nile, but were part of a larger system of flowing waters hidden underground.

Other representations were not quite so fanciful, depicting the mountains as a range at the interior end of the Nile—although most also speculated that the twin source lakes also existed. It wasn’t until the 18th century that reasoned European cartographers began omitting the apocryphal features. In 1700, French cartographer Guillaume Delisle left the Mountains of the Moon off his new map of Africa, having been unable to verify their existence. Other cartographers began to include the features less and less, or in forms that partially reflected new information. Gradually, the Mountains of the Moon disappeared.

In actuality, the Nile River branches off into two distinct tributaries at Khartoum in Sudan. These waterways are known as the Blue Nile and the White Nile, giving the Nile two sources. The source of the Blue Nile was found to be at Ethiopia’s Lake Tana, while an expedition in the 1850s led by Richard Burton and John Speke traced the origins of the White Nile to Lake Victoria. If Ptolemy’s account of the Mountains of the Moon were correct, it was likely Lake Victoria (and nearby Lake Albert) that were being described in front of the Rwenzori Mountains in eastern Africa. Although due to the myriad geographical inaccuracies found in the comparison (mainly the placement of the lakes on the continent), it is also thought that the account could have been pure fiction.

The Rwenzori Mountains, known as the Mountains of the Moon (Photo: Wikipedia)

Today, the Rwenzori Mountains are still often referred to as the Mountains of the Moon, although this is a nickname rather than a literal appellation. With the actual sources of the Nile charted and mapped, one more magical piece of the world has been proven false, but we’ve still got the incorrect old maps of yore to tide us over.