To: Bletchley Park.

From: Facebook.

What: A lot of money.

Facebook made a million-pound ($1.3 million) donation to Bletchley Park, the Victorian country house in England where modern computing was born. Why? Because without Bletchley Park, Facebook wouldn’t exist.

During World War II, codebreakers worked day and night at Bletchley Park. Their top-secret mission was decoding encrypted military messages from Nazi Germany.

 The whizzes at Bletchley Park had to crack the codes made by the Enigma machine, Germany’s cipher creator. Before World War II, people did the jobs computers do now. Difficult calculations could take hours. And they had to check each other’s work too.

Human computers couldn’t begin to keep up with Enigma. No simple typewriter, Enigma rotated the letters of the alphabet, creating a constantly changing cipher. Enigma could mix 103 sextillion possible codes!

Enter British mathematician Alan Turing. A few years earlier, Turing invented the idea of modern computers. At Bletchley Park, Turing designed an electromechanical machine called the Bombe. Bombe cracked Enigma’s codes, and soon the British could read all the German Navy’s communications. Many say this work made the war two years shorter than it would have been and saved millions of lives. Turing’s ideas also made the first digital computers possible.

Imagine a world without Bletchley Park codebreakers—Enigma’s code uncracked, Nazi Germany the victor of World War II, and the computer never invented. Computers have come a long way from the hot, noisy, room-sized calculators they were at first. Now tiny computers fit almost anywhere and solve problems a lot faster than people can. That’s why they’re ubiquitous (practically everywhere). Little ones inside machines make planes fly and cars drive. Do you see someone wearing a computer inside a wristwatch? How about someone carrying a phone? All these machines make complex calculations in less than a blink.

When the war ended, Bletchley Park became a museum. People went there to learn about coding. (Coding, or computer programming, is how people give instructions to a computer.)

But now Bletchley Park is in trouble. Hundreds of thousands of people visit during a normal year—but 2020 has not been normal for anyone. Like places all over the world, Bletchley Park couldn’t receive nearly as many visitors as usual during the coronavirus pandemic. It lost almost all its income.

Steve Hatch is Facebook’s vice president for northern Europe. He says Facebook’s technologies wouldn’t have been possible without the work done at Bletchley Park. The donation will help keep the park running and let staff keep their jobs.

“Our hope is that Bletchley staying open inspires the next generation of engineers,” says Hatch.