BLETCHLEY PARK is one of the world’s great survivors.

The mansion, 50 miles northwest of London and dating to the late 1870s, was almost lost to the British nation twice. In 1938 a local builder was eyeing the parcel as a development site when the government stepped in, buying the property from the Leon family to house a Code and Cypher School.

And in 1992 bulldozers loomed again until local historians barred their path. Forming the Bletchley Park Trust, advocates saved the complex, where a secret wartime operation broke the German Enigma code, and recast the Park as a museum. Now appreciation for that act of preservation is reaching beyond Britain; of the site’s 150,000 yearly visitors, more and more hail from overseas. Those ranks will only swell thanks to The Imitation Game, the Oscar-winning movie about code-breaking genius Alan Turing.

The Imitation Game Poster

If you love The Imitation Game, be sure pay a visit to Bletchley Park where all the real events happenned here

During the 1920s and 1930s, the Park had been a country idyll, popular with shooting parties, until that 1938 purchase began the estate’s transformation into a hub of Allied counterintelligence work during the Second World War.

I visited on a raw December day with my father. Born in 1938, Dad grew up five miles away; he found it moving to return to a place he had not seen since leaving for Oxford University in 1956. As we neared Bletchley station he noticed through the railway car window a parking building on the spot where, during the bitter winter of 1947, he told me excitedly, had sprawled the coal yard to which his mother would send him to fetch household fuel.

The government chose Bletchley Park as a code breakers’ perch primarily for its location. With war against Germany imminent, Whitehall wanted its code wizards away from London and Luftwaffe bombs. The manse sits at a safe distance from the capital city, but within 200 yards of a railroad station. Nearby are the universities of Oxford and Cambridge, in the late 1930s fertile environments for recruiting the brilliant minds required for high-level intelligence analysis.

Entering the estate, one at first sees only motley brick-and-timber huts, splayed at odd angles like drab dominos. The bleak, utterly authentic scene makes it easy to picture streams of extremely bright young things, male and female, arriving hurriedly by foot and on bicycles three-quarters of a century ago.

bletchley park

The tour begins in the Visitor Center–wartime Block C, where clerks, mostly women, indexed the details of decoded messages in a giant cross-referencing system. The assignment was painstaking, a point made clear in footage of reenactments that runs continuously.

“To be successful,” an instructor tells newcomers, “you must be an enthusiast because there will be times when the work seems monotonous.”

Monotonous, yes–but vital. Eventually, Bletchley Park and environs employed 10,000 people. Some intercepted, some deciphered, some translated, some distributed, but all the intelligence they winkled out of myriad enemy radio signals mattered critically to the Allied cause.

British Prime Minister Winston Churchill called the Bletchley Park team “the geese that laid the golden egg.” In July 1945, General Dwight D. Eisenhower sent a message to British Major General Stewart Menzies, who headed the operation. Describing the intelligence gleaned there as “priceless,” the Supreme Commander said the Bletchley Park workforce had “saved thousands of British and American lives and, in no small way, contributed to the speed with which the enemy was routed.” The museum displays a copy of Eisenhower’s communique.

Visitors depart the center bearing an easy-to-use audio device that directs them around the rest of the grounds–another mark of the museum’s thoughtfulness. I, for one, am not blessed with undue mathematical competency, and would be lying if I suggested that prior to my visit I wasn’t a bit apprehensive. Ultra, Enigma, Bombe, Lorenz … Would I be able to keep up or would the topic’s complexity befuddle me?

Fear not. All is explained in lay terms, and old-schoolers can sign up for a comprehensive tour conducted by one of the site’s knowledgeable guides. We went with the talking machine, but did cross a guide’s path in Block B. Standing before a replica of Alan Turing’s Bombe, he explained to his companions how the computing mechanism worked.

“Turing,” the docent concluded, “is one of the great unsung heroes of British history and were it not for him we might be here speaking German.”

There is much to learn about Turing in Block B. The centerpiece is the Bombe, a functioning model of which testifies to its inventor’s genius. The mechanism is seven feet tall and six and a half feet wide. The original had 108 drums, each vertical set of three representing a German Enigma encoding and decoding machine. Early Enigmas had three rotors (later the Reich would add a fourth). A sender scrambling a message could set each ring at any of 26 positions; in effect an Enigma machine had 17,576 (263) settings. The Bombe’s drums could drive through every potential setting in about 12 minutes by electrically performing a chain of logical deductions based on a portion of plain text. Turing’s device rejected combinations that produced contradictions–as the majority did–supplying the code breakers with a small number of possible Enigma settings. If that sounds complicated, don’t worry–interactive touch screens and straightforward diagrams help “decode” Turing’s achievements in smashing the enemy code.

More personal exhibits illuminate the man behind the genius: Turing’s Swiss wristwatch and his teddy bear, Porgy. Perhaps that tatty stuffed plaything more than any other artifact at Bletchley Park affords a glimpse of Turing’s human vulnerability. And the secrets keep coming; recently during a renovation workers uncovered notes of Turing’s stuffed between the walls of Hut 6 as insulation, along with the only known examples of Banbury sheets–forms that the mathematician devised to speed decoding.

The visit ends in the mansion, an elegant Victorian building that overlooks the Nissen huts and a lake aggregated more than 200 years ago from the remains of medieval fishponds. Entering “The Main House,” as wartime workers called it, is a pleasing step back to the Old England of yesterday and recreated BBC memory. The red brick mansion fuses Tudor and Dutch Baroque architecture, with an eye-catching array of bay windows, tall chimneys, and crenelated parapets. One enters through a Gothic-style inner porch to encounter an interior of mahogany paneling, decorative plaster ceilings, elegant carpets, and whiffs of yesteryear. To the right of the porch is the lounge hall, on whose elaborate stone and marble chimneypiece stands a bust of Winston Churchill. A timber staircase leads to the first floor; the highest story is the attic, a century ago quarters for servants.

BLETCHLEY PARK

Bletchley Park House

Until November 2015 much of the mansion’s interior will house an exhibition featuring The Imitation Game. In the billiard room are the costumes worn by actors Benedict Cumberbatch (Turing) and Keira Knightley (the mathematician’s colleague, Joan Clarke). The ballroom holds the bar depicted in the film, and my father yelped with delight as he recognized brands of beer and soft drinks he had last seen 60 years ago. The exhibition also reveals that among the film’s cast of extras was a great nephew of Turing’s. How delighted he must be at his great uncle’s rehabilitation in recent years: Britain’s official apology in 2009 for hounding him to his death and, four years later, a posthumous royal pardon. Pardon for what? For the now-banished crime of homosexuality. In 1952 Turing’s country prosecuted him for being himself, driving him to suicide two years later, a stain on the British establishment well documented in The Imitation Game.

It’s taken 70 years and $12 million, but Bletchley Park offers Turing and company a fitting memorial.

As Her Majesty said in 2011, unveiling a sculpture at the estate honoring the code breakers: “This was the place of geniuses such as Alan Turing. But these wonderfully clever mathematicians, language graduates, and engineers were complemented by people with different sets of skills, harnessing that brilliance through methodical, unglamorous, hard slog…. You were history-shapers and your example serves as an inspiration to the intelligence community today.”

WHEN YOU GO

Only an hour by train from London Euston–one of the British capital’s central stations–Bletchley Park Is a stroll from the local train station. The Park Is on Sherwood Drive, Bletchley, Milton Keynes, Buckinghamshire, England; 44-1908640404, bletchleypark.org.uk

WHERE TO STAY AND EAT

Hut 4, where clerks decoded German naval messages during the war, houses the museum’s restaurant. Expect traditional British food-such as fish and chips, stew, sausages, a wide selection of sandwiches, and a choice of soft drinks and beer–at reasonable prices. Four miles away, Milton Keynes, the nearest big town, has plenty of budget and mid-range hotels, and someone staying in London easily can manage a day trip.

WHAT ELSE TO SEE

The National Radio Centre and the National Museum of Computing are In close proximity to Bletchley Park (admission to the former Is Included in the price of visiting Bletchley Park) and are well worth a visit. The Computing Museum houses a rebuild of Colossus, the world’s first programmable electronic digital computer.