All the Slow Horses' hideouts: From sleazy Slough House to Jackson Lamb's greasy spoon, our spies track down the MI5 rejects' leading locations - real AND imagined

It's not a world you would necessarily want to spend much time in, but seeking out the real-life locations of the gloriously dingy (and fabulously flatulent) TV spy series that has gripped millions across the world is a mission well worth undertaking.

Apple TV’s smash hit Slow Horses sees Jackson Lamb (Gary Oldman) and River Cartwright (Jack Lowden, tipped as the next Bond), traverse a mostly murky London as their band of MI5 rejects fight to foil terror attacks and other varied nefarious plots.

The capital plays a central role, and now, with the sixth series under way, The Mail on Sunday went on assignment to track down the top-secret filming locations in and around London.

And – just to baffle even the most ardent fans of the drama – some are real, others are not.

As aficionados know, this group of disgraced secret agents draw their Slow Horses sobriquet from Slough House, their rundown HQ. It is the title of the first book in author Mick Herron’s series of novels (nine so far).

The MoS can reveal the scruffy base is in upmarket Aldersgate Street, near the Barbican in the City of London. Herron used to pass it every day on his commute.

But the stairs leading from the back of the office belong to 15 St John St, five minutes away.

The Aldersgate office sits just above Vecchio Parioli, a real-life family-run Italian restaurant.

This features regularly in the series, most recently with the slovenly Lamb tucking in to a meat-based tagliatelle and a bottle of red when confronted by Emma Flyte, the head of internal security at MI5, played by Ruth Bradley.

Another classic haunt for Oldman’s character is Beppe’s Cafe on West Smithfield, where he can be found fuelling up for the day with a sizeable fry-up.

It is a seven-minute stroll from the office through Smithfield Rotunda Garden. Beppe’s Cafe, owned by the same family since 1932, maintains many of its original features, including its green-tiled walls and booth-style tables.

Over in trendy Haggerston, the Towpath Cafe on the Regent’s Canal is another favourite. Brooding agent J.K. Coe, played by Tom Brooke, and the volatile Shirley Dander (Aimee-Ffion Edwards) dine there in the latest series.

But all is not what it seems in the highly successful spy drama. Take the New Empire Cafe on Aldersgate Street, for example. In reality it is a venue called Gate Grill Cafe, and a different sign is added for filming.

If Slough House is the dreary administrative centre of the dead-end agents’ world, The Park is the shiny citadel hosting mainstream MI5 work. 

It is where Lamb’s nemesis Diana Taverner, played by Kristin Scott Thomas, the ruthlessly ambitious head of operations, rules the roost. It is fictional.

The incredible bird’s-eye shots of The Park are created using CGI, placing the fictional building in Regent’s Park where, in real life, there is a running track.

Its ‘Regent’s Park Zoo’ is a play on London Zoo, but in series five, scenes for an explosion there appear to have been shot in Kew Gardens.

Regent’s Park itself is a regular backdrop for serious conversations, memorably when Lamb and Taverner are trying to outplay each other. The locations used include the boating lake, the park’s North Gate entrance and benches by the canal.

As for The Park, the crew also filmed in and around the Old Royal Naval College in Greenwich and on the campus of Greenwich University. The Dreadnought Building (the university’s student union) is featured when Oldman walks through the college greens, but with CGI-imposed modern buildings behind. 

Then there is the underpass where Lamb summons his team for a debrief. Meant to be in the zoo, it is instead at Charlie Chaplin Walk on South Bank.

Another frequent rendezvous is the burial spot of poet and painter William Blake in the dissenters’ cemetery at Bunhill Fields, Old Street (the name means Bone Hill). 

In episode two of the recent series, Lamb calls a meeting there with his team, including assistant Catherine Standish (Saskia Reeves), instructing them to head to a safe house amid a spree of murders targeting them. 

Where that is, of course, we can’t tell you.