The Mountains of the Moon

An ancient “fable” that turned out to be literally true

Around 150 AD Claudius Ptolemy drew a map of Africa, partly from what Arab traders had told him, and put a range deep in the interior that he called the Mountains of the Moon. He said the Nile rose there. For the next seventeen hundred years that was either the oldest surviving intelligence about the heart of the continent or a rumour everybody kept copying, and the Victorian expeditions went out in part to settle which.

He was right. The Rwenzori run along the border between western Uganda and the Democratic Republic of the Congo, and Margherita Peak on Mount Stanley reaches 5,109 metres, the third highest point in Africa. Unlike Kilimanjaro and Mount Kenya, which are volcanoes, this is a block of ancient basement rock shouldered up along the western arm of the Rift Valley in the late Pliocene, less than five million years ago. And it carries glaciers, on the equator, feeding rivers that reach the White Nile. That is exactly what Ptolemy was told.

The Ugandan side was gazetted as a national park in 1991, became a UNESCO World Heritage Site in 1994 and a Ramsar wetland in 2008. The reason to go is not the summit. It is the vegetation. The middle slopes hold an afro-alpine zone that looks like nowhere else on Earth: tree heathers ten metres tall hung with lichen, giant lobelias and groundsels, everything soaked and mossy and out of scale.

The ice is nearly gone. Rwenzori glaciers have retreated by more than eighty per cent since 1906, lost over three quarters of their area across the twentieth century, and halved again between 1987 and 2006. Current estimates give them decades at most.

Trekking is by permit through the park with operators out of Kasese, and the standard circuit is a hard, wet week on rock and bog. Go before the snow Ptolemy heard about finishes disappearing.