A quarter of a century ago, the Berlin Wall was torn down, rejoining two cities into one. Cartographers responded in different ways to the wall's erection and destruction - usually choosing to emphasise either unity or disunity, depending on their politics.
CJ Schuler, a cartographic historian, has tracked the ways the wall was represented by maps on mapping blog Here.
Here's five things we learned from his piece.
1. Some East German maps left off West Berlin altogether.
This 1988 map from East Germany shows the western part of the city as a gaping hole, surrounded by a thick pink line:
2. Two U-Bahn lines went under the wall.
The lines didn't actually connect East and West, but the configuration of the metro system meant some western trains passed through 11 abandoned stations under the eastern part of the city. Only one train station, Friedrichstrasse, actually allowed passage between East and West Berlin.
3. Western U-Bahn maps made the city look connected.
This subway map used in West Berlin appears to show the city's transit network as one contiguous system:
Only by reading the small print could travellers find out that the eastern stations were "only accessible by the BVG East and DR". There was actually only one train station in the city where you could pass from east to west, and it was, as you'd expect, controlled by guards and checkpoints.
4. Eastern U-Bahn maps, meanwhile, fiddled geography to make it look like West Berlin didn't exist.
As with the geographical map above, East Berlin's U-Bahn map used a clever trick to miss out West Berlin altogether: it superimposed a map of the East German suburb of Potsdam, which lies further west, on top of West Berlin, and makes its lines part of a radial network with its centre at Alexanderplatz.
Image: Frank Jacobs’ Strange Maps.
5. After reunification, the Berlin Senate set up a commisison to change East Berlin's Soviet place names.
Around 80 streets were renamed in total. Leninallee became Landsberger Allee (wonder why they felt they should change that?). Otto Grotewohl Strasse, named after the East German prime minister, reverted back to Wilhelm Strasse, its original name
You can read Schuler's full article here.