IT could be something straight out of James Bond.
But what from the outside looks like ordinary shipping container, is actually hiding a dazzling array of secret gadgets for British spies.
The Sun Online has had the first look inside UK spy agency GCHQ's field office for agents in war zones.
It contains enough classified technology to start World War 3 – and even has a supply of Pot Noodles to keep our spies fed.
Clues as to the work that field officers do – and the dangerous places they can be based – are strewn across the desk.
Giant servers hum in the corner, and in the door are destructive tools, ready at any moment to destroy all the equipment inside the office in case their base in war zones is breached.
Flashing servers sit in a TEMPEST cage, a physical shield which hides GCHQ's signals that might reveal confidential data.
A satellite dish sits on top of the reinforced container to provide a communications link between bases.
And as a reminder of the dangerous territory these field offices can sit in, an escape hatch can be seen in the corner for officers needing to flee at any moment, with body armour stashed in a corner to protect the workers, isolated on frontline bases, during any attacks.
A fictional, report funnelled to GCHQ staff sits on the computer, reading: "Operation YELLOW BOX is the investigation into a group of extremists planning attacks against UK forces in Afghanistan.
"According to previous GCHQ reporting, an unidentified male located in the Helmand Province has ties to known extremists. According to collateral TOP SECRET, he has been linked to possible attack planning in Kandahar province."
It's an example of the type of information the officers would receive before passing it onto the military to take action.
The Government's electronic eavesdropping agency have used these field offices across remote military bases in the early days of missions in Iraq and Afghanistan, providing the military with intelligence as they monitored threats like the Taliban.
The information would help stop plots to target British convoys and foil physical or digital threats to the UK.
And it was these offices that were part of the biggest overseas deployment since the Second World War as they organised listening posts across southern Afghanistan.
The work of the GCHQ in Afghanistan was only revealed in 2014 when they flew out more than 400 tonnes of equipment – equivalent to 100 shipping containers' worth.
The staggering amounts of equipment was six times more kit than the agency deployed during Britain’s post-2003 Iraq campaign.
Speaking to the Sun Online, a government communications officer – who can only be known as Fi – revealed how they would work up to 30 hours in the steel container during top secret missions.
She said: “We can be up and running with top secret communications as soon as we arrive in different locations.
“We provide the right intelligence to the military they need to keep them safe.”
The huge containers can even be choppered into site thanks to huge Chinooks.
And she said the shipping containers were designed to fit in at any base camp or field office, giving no hint as to the vital work going on inside.
WHAT'S INSIDE: GCHQ's field office
Servers: These servers store all the top secret information for the GCHQ needed during foreign missions
Body armour: This body armour is ready to be grabbed at any moment, to be worn in military bases during a time of attack
Destructive tools: In case the secure base was breached, GCHQ officers were given training as to how to destroy the contents of the shipping container to ensure it did not fall into the wrong hands
Diplomatic bag: These plain bags would be used to carry sensitive information around the camp
Escape hatch: In case of an emergency, officers would be able to scramble through the emergency exit hatch
Gift vouchers: These tokens are used in camps like Camp Bastian in Afghanistan as a form of change
On Her Majesty’s Service envelopes: Information would be posted in these envelopes
Pink discman: The servers would make constant noise, with officers using music to block out the consistent hum
Keep Calm and Carry on poster: Homely touches helped to make officers feel more comfortable in the foreign surroundings
Cup of Noodles: Working such long hours, sugar and food would always be in constant supply in the offices
Maps: Part of the work done by GCHQ officers was to ensure the military knew as much as possible about ongoing missions or what was happening in certain areas
Diarrhea tablets: According to communications officer Fi, this was one of the facts of life while based overseas
Fly paper and jungle formula: In the baking heat of some bases, keeping the pests at bay with insect repellent was important
Water purification tablets: Sometimes supplies could be in short supply, meaning water puritifcation tablets were extremely important for workers
Temperature gauge: High temperatures in the field are kept in check in the field office, with sensitive computer equipment needing to be kept between 20 and 21C
Fi, who was deployed to Afghanistan three times for stints of five to seven months and Iraq for 13 weeks, said she had remained determined to do her work throughout.
She said: “I think about why we are out there, we are there to support the military.
“On the worst days, you think about what you are doing and that gives you quite a bit of motivation to get out of bed. You’re part of the team.”
The GCHQ had been established after the First World War, known as the Government Code and Cypher School until 1946.
Responsible for breaking the German Enigma codes, its work has continued to see it gather information and secure's the UK's own communications.
And the work has changed from cold war-era listening posts to include digital surveillance – monitoring increasingly cyber threats posed by countries like Russia, North Korea and China.
Most recently, the GCHQ revealed it had played a major part in a cyber campaign against ISIS and its propaganda.
REMINDERS OF HOME
But amongst the frantic security work that goes on inside this unassuming box, touches of home are added.
A Keep Calm Carry On poster is tacked on the wall, cups of noodles are piled in the corner and a scarf sits draped over the office chair.
Tea and biscuits are also at the ready during the long shifts and military visits.
Fi said: “Earl grey and shortbread was popular – being able to give people tea and biscuits in the very British way was a way to build relationships.”
A picture of a bunny rabbit sits attached to one of the servers – with the animal having been gifted to one of the soldiers by a local he was teaching English.
The pet, dubbed Honey Bunny, then became a camp favourite.
As the threats to the UK become more diverse and more complex – it’s a chance to encourage the next generation of recruits. Because at GCHQ we believe that with the right mix of minds anything is possible
It is these stories, and the fascinating work done by GCHQ, that will be marked in the Science Museum’s new exhibition that opens on July 10.
GCHQ, or the Government Code & Cypher School (GC&CS) as it was known at the time, was established on 1 November 1919 as a peacetime cryptanalytic unit made up from staff from the Admiralty's Room 40 and the War Office's MI1.
During WWII, GCHQ staff moved to Bletchley Park where they decrypted German messages, most famously by breaking Enigma-encrypted communications, making a significant contribution to the Allied victory.
The organisation moved to Cheltenham in 1950, and then settled into its current building, famously nicknamed the "Doughnut" in 2003.
They now have sites across the country, including Bude, Scarborough, Harrogate, Lincolnshire, and London, and a new facility in Manchester will be opened later this year.
Jeremy Fleming, Director GCHQ said: “This unique collaboration between GCHQ and the Science Museum is a great way to mark our Centenary and give visitors previously-unseen insights into how GCHQ has helped protect the UK over the past 100 years.
“For the first time the public will be given a glimpse into our secret history of amazing intelligence, world-leading innovation, and most of all brilliant people.
“And – as the threats to the UK become more diverse and more complex – it’s a chance to encourage the next generation of recruits. Because at GCHQ we believe that with the right mix of minds anything is possible.”
Hannah Daley, the Science Museum’s exhibition project manager, said she was thrilled that more than one hundred items would be on display for members of the public.
She said: “It’s an insight into a secret world we don’t normally get to see, and how they support the military.
“There are powerful stories about how they do that work, and life their life in secret.”
- Top Secret: From Ciphers to Cyber Security runs from July 10 to February 23 2020 for free, located in the Basement Gallery of the Science Museum.