For the first time ever, MI5’s history and documents are on display for the world to see at the National Archives, marking 115 years of the institution.
This fascinating exhibition explores the history of espionage and National security, showcasing original case files, documents and even equipment used by spies.
The exhibition ends this month (November 23rd 2025), so if you’re interested in visiting, you best be quick!
Keep reading for my review of the MI5: Official Secrets exhibition.
Firstly, I just want to note that I was very impressed with the staff members, who let me know about the queue length (only around 20 minutes), and gave me some reading material while waiting!
I was given a folder all about William Ewer, a journalist accused of being a Soviet spy. An interesting read while waiting for my turn inside the exhibit.
The exhibition itself was absolutely worth the trek all the way out to Kew (and yes, I did pair it with a trip to Kew Gardens afterwards).
From correspondence and photographs to real-life espionage equipment, there’s a lot to see here (nearly a hundred items), which is particularly impressive for a free exhibit.
I found myself wanting to read every single letter, but didn’t want to spend too long at each display because I knew there were others waiting.
“Ordinary people doing extraordinary things.”
What You Can See at the MI5: Official Secrets exhibition:
- Original MI5 case files, declassified and on display for the first time, covering WW1, WW2, the Cold War and beyond.
- Correspondence debating the merit of female intelligence agents.
- Notes from the infamous Cambridge Spy Ring, featuring names like Guy Burgess and Kim Philby, whose betrayals shook Britain’s intelligence community to its core.
- A look at the modern MI5, tackling today’s threats like cybercrime, terrorism, and disinformation.
Exhibition Highlights
- A 110-year-old lemon, found at Karl Muller’s home (suspected to be a German spy), used for creating invisible ink.
- The first camera used by MI5 for surveillance, from 1910.
- A note that reveals that Girl Guides were more reliable than Boy Scouts for intelligence errands!
As you make your way through through the exhibition, you’ll encounter mockup rooms, audio to listen to, and a video projection.
After wandering through the initial rows of filing cabinets looking at letters and photographs, walking into this open space made me go ‘ooooh nice!’.
Overall, I was very impressed with the exhibition, the staff and the fact that it was free.
This one ends on November 23rd, so be sure to make the trip to Kew if you don’t want to miss out. It’s around a 10 minute walk from Kew Gardens station (District line + Overground).
For more information about visiting the MI5: Official Secrets exhibition, check out the National Archives website.
There’s no need to book a ticket, simply scan the QR code for the virtual queuing system when you arrive!