A map showing how the Post Office Tower was never a secret, next to an Enigma machine that was a flawed attempt to keep secrets, are two highlights of an exhibition about secret maps.
It’s an exhibition with the word “secret” literally written all over it, as many of the maps are from WWII and the Cold War, and were classified with various levels of secrecy. Often, the word “secret” was crossed out when they were declassified.
We often forget that the maps we use to get around town to find the latest Insta-friendly coffee shop are political tools of government control. They show borders that define where we are different from them, where the right sort of people live, or are barred from visiting, and where control over food and water, and even tracking droughts and famines, is exercised.
The exhibition examines how maps and mapping technology have changed over the centuries and how maps have often been used for political ends.
It starts with some of the earliest maps, often drawn to show Kings what they own, or covet, and of course, who owes them taxes. Early maps were used by lords to show how rich and lordly they are, but in recent years, maps have turned the tables to reveal how the rich prefer to avoid paying their tithes by hiding their wealthy ownerships.
But what is probably most fascinating are the once-secret maps that aren’t any more that reveal how subversive government control could be at times. Some of the maps are obvious, military installations and the like. A map of submarine cables for international communication is likely secret because they are a critical piece of infrastructure. But the locations of the cables were widely known – so why the secrecy? Look for the purple underlines on the map – they mark UK spy centres where the British could listen in on messages. Ohh!
The exhibition also looks at how mapping technologies have changed over the centuries, with the big leap forward really taking place with the advent of aerial photography (and later satellite imagery), allowing one country to check if the published maps of another are correct. Often not in the Soviet Union, as shown in an example of how maps concealed a factory complex as being residential.
And still not in China, where you might notice that the official road layouts don’t match Western satellite images.
As tools of politics, maps didn’t just record what the world looks like as they also reflected the biases of the mapmakers. A section examines how areas that were inhabited might be depicted as empty to encourage colonisation, or to repress overlooked people. Look at a map of South Africa under apartheid, and vast chunks of cities are missing as maps ignored the black majority population.
There are secret maps showing various options for the partition of India, a reminder of how the decision was imposed from on high without local input, as the documents were kept secret from the people who were to be affected. Feels a bit like how the USA and Russia play games at carving up Ukraine without bothering to ask the Ukrainians what they want.
Maps can also be made by the oppressed, from the CND maps of Greenham Common to the gay cruising ground maps when being gay was illegal. Some of my favourites were the WWII escape maps, often printed on silk, used by spies in mainland Europe. After the war, thanks to austerity, the silk maps were repurposed as ladies’ underwear. The maps were only a Secret now if your name was Victoria.
More somberly, a map of London following an assumed nuclear attack – mostly the docks of East London, plus a couple in the centre – and fascinatingly, one over Neasden – which we now know was the location of the reserve Cabinet War Rooms, but at the time the map was made, one of the government’s most closely guarded secrets.
And in a room full of secret maps, there is a map that was never secret, but people said it was. It’s the 1966 OS Map that clearly shows the Post Office Tower, debunking the oft-repeated myth that it was a state secret. As Matt Brown has already shown, it wasn’t.
As an exhibition, it ranges from truly ancient maps right up to modern GPS and fact checkers, showing how maps have been used and abused down the centuries. But so much more than that – it’s a sumptuous feast for the eyes.
And maybe play a game of counting how many times the word “secret” appears on the maps.
The exhibition, Secret Maps, is at the British Library until 18th January 2026.
Standard Ticket: £18
Concessions: £9
National Art Pass: £9
16 – 25 Years: £6
Universal / Pension Credit: £3
Child (Under 16 Years): Free
Tickets are available from here.
