A collection of rare maps of Africa, dating from 1530 to 1915, has been made freely available on the internet by Northwestern University in the US.
Curator David Easterbrook says the antique maps not only show the growing geographical knowledge of Africa but the progression of colonisation.
"Early cartographers had not visited or surveyed the land, so they had to do their best guesswork," he told the BBC.
All of the 113 maps can be examined in detail on the site or downloaded.
"The earliest maps show just how unreal the knowledge of Africa was in Europe at that time," Mr Easterbrook says.
The cartographers were often working from multiple and often varying accounts.
In some early examples, the River Nile is in the wrong place and many mountains, lakes and sources of precious minerals were based on hearsay.
"You can see overtime how the shape of Lake Victoria [in East Africa] changes from a sock-like elongated profile to a more rounder shape," he says.
Mr Easterbrook also argues that the maps, many of which are highly decorated with artistic flourishes as well as topographical features, should also be savoured for their aesthetics.
The African slave trade is depicted in this map from 1892
"They are just fascinating to look at," he says.
Old African kingdoms are also mapped, like Abyssinia in the oldest map of the collection.
The map of Dahomey in West Africa is illustrated with depictions of the slave trade, and another shows the southern empire of Monomotapa.
A map of West Africa from 1747 refers to the region as "Negroland".
The most recent map in the collection from 1915 shows the town plan for Dakar, Senegal's capital.
The collection, which can be browsed by date, country, and other categories, forms part of the university's Herskovits Library - the largest separate library for the study of African studies in the US.