Macabre murders, headless horsemen roaming the county, and grisly deaths in the countryside...
Hertfordshire is a popular haunt for TV production crews making crime dramas, detective thrillers and murder mysteries.
Despite being set elsewhere in the country, did you know Inspector Morse, Midsomer Murders and Jonathan Creek have all been shot on location in Herts?
We've done some sleuthing of our own, and here's 8 television series that have been filmed in Herts at some point.
1. Midsomer Murders
Following the recent new series of the ever-popular ITV show, catch the earlier exploits of Neil Dudgeon as DCI John Barnaby on BritBox, including one of his favourite episodes from series 15 filmed in Knebworth.
The appearance of a headless horseman at Quitewell Hall foreshadows a number of deaths in 2012 episode The Dark Rider.
"It is one of my favourite episodes because of a rather strange and bizarre denouement, some wonderful deaths, and one of my favourite episode openings that we've ever done," says Neil Dudgeon on BritBox introducing the episode.
Knebworth House doubles for Quitewell Hall – with the first unfortunate victim falling to his death from the mansion's roof late at night after seeing a headless horseman.
While there's no 'death by cheese' as suffered by the unfortunate Martine McCutcheon in a different episode, one unsuspecting victim, Ludo DeQuetteville, gets crushed to death by a dislodged stone gargoyle.
The Knebworth estate also hosts a Civil War re-enactment in this series 15 episode that gets rather out of hand between the warring Roundheads and Cavaliers, with John's wife Sarah Barnaby (Fiona Dolman) unable to control proceedings for the Causton Historical Society.
The episode is also a personal favourite of Fiona Dolman, who previously starred in ITV drama Heartbeat.
2. Jonathan Creek
Curly-haired comedian and actor Alan Davies stars as the titular magic trick designer turned sleuth who is often called in to solve puzzling cases.
The feature-length January 1, 2009 special The Grinning Man sees Jonathan Creek get a new sidekick in paranormal investigator Joey Ross, played by Sheridan Smith.
Supposedly set in Berkshire, the Gothic mansion Metropolis in this episode is actually Knebworth House, as you'll see if you watch the episode on BritBox.
3. Inspector Morse
Although this detective drama is based in the university city of Oxford, it is another TV series to have taken advantage of the Hertfordshire countryside, its magnificent mansions and pubs, and St Albans' historic streets.
Starring John Thaw as the cantankerous Morse, episode Masonic Mysteries sees the titular character sitting in the Romeland garden in front of St Albans Cathedral.
We all know Inspector Morse likes to discuss a case over a pint or two, and where better in St Albans for him to enjoy an al fresco drink with Lewis (Kevin Whately) than outside the historic Ye Olde Fighting Cocks?
That happens in 1990 episode The Sins of the Fathers, an episode in which Morse investigates the suspicious death of a brewery manager.
As Lewis sups his pint in the sun at the picturesque location, Morse castigates him: "Don't slurp in my ear, Lewis!"
They didn't even change the name of the public house, with the Ye Olde Fighting Cocks sign clearly visible behind Lewis.
Morse also pays a visit to Brocket Hall in the following year's series five episode Who Killed Harry Field? with the stately home on the outskirts of Welwyn Hatfield doubling for Paul Eirl's mansion.
Morse and Helen Field, played by Geraldine James, visit a pub, which is now actually the Auberge du Lac restaurant on the Brocket Hall estate.
Morse and Sergeant Lewis also visit the nearby The Crooked Chimney, in Cromer Hyde Lane, Lemsford, as part of the investigation into Harry Field's murder, and Morse later returns for a pint, naturally.
Morse and Lewis then cross the B653 Marford Road onto the Brocket estate, to where there's a long view down to the mansion.
Morse even says to Lewis: "...300 yards from where Harry's motorcycle was found is the back of the estate."
He later drives his famous burgundy Mark II Jaguar to the house.
Hertford has also been used for location filming of Morse, with the inspector popping in for a pint in The Old Barge by the river.
4. Grantchester
While Morse is based in Oxford, this Robson Green series is set near the university city of Cambridge.
However, the vicarage in the series isn't in the Cambridgeshire village of Grantchester but in Hertfordshire in a private property in Lemsford.
In 2018, Robson Green was also spotted in the streets of St Albans during production of the 1950s drama.
You can watch all episodes from the first five series on BritBox.
5. Foyle's War
Commissioned after Inspector Morse had finished and created by writer Anthony Horowitz, this ITV World War Two drama sees Michael Kitchen star as Detective Chief Superintendent Christopher Foyle investigating crime on the home front.
Although set on the south coast in Hastings, Sussex, Old Hatfield was used as a location of Foyle's War.
Series 3 episode A War of Nerves sees an appearance of The Eight Bells pub in Old Hatfield, as well as Church Street and Fore Street.
The top of Fore Street can also be spotted in episode Enemy Fire.
Foyle and Honeysuckle Weeks as his driver Samantha Stewart are also seen in the grounds of St Etheldreda's Church.
6. Agatha Christie's Poirot
We couldn't forget Poirot and his 'little grey cells' in this round-up.
David Suchet as the famous Belgian detective is no stranger to Hertfordshire's stately homes, with episodes of Poirot having been filmed on location at Knebworth House, Hatfield and Brocket Hall.
Agatha Christie’s Poirot – Hallowe’en Party includes scenes filmed in Old Hatfield, with St Etheldreda’s Church again used as a location.
Poirot visits Knebworth House for series 12 episode Three Act Tragedy and Brocket Hall features in penultimate episode The Labours of Hercules.
All 13 series of David Suchet as the moustachioed private detective Poirot can be watched on BritBox.
7. Agatha Christie's Marple
Another of Agatha Christie's famous literary creations, Miss Marple, has also tackled murder mysteries filmed at Hertfordshire's historic stately homes.
The sharp-eyed sleuth has appeared in scenes shot at both Knebworth House and Hatfield House.
8. Year of the Rabbit
This irreverent Victorian-era TV sitcom from Channel 4 plays the crime genre for laughs.
Matt Berry stars as Detective Inspector Rabbit, a sweary, hardened booze-hound who fights crime in Victorian London. Think a Victorian style Gene Hunt!
He's helped by keen-but-clueless new partner Sergeant Wilbur Strauss (Freddie Fox) and Mabel Wisbech (Susan Wokoma), the chief of police's foul-mouthed adopted daughter who becomes the force's first female officer.
Look out for Knebworth House in episode four with Keeley Hawes as Lydia, the leader of The Vision, a secret women's organisation, shooting arrows in the gardens with Mabel.
Keeley Hawes and Jill Halfpenny, as Flora Wilson, also shot scenes in the Banqueting Hall for the final episode.
The episode six climax, featuring Joseph Merrick, aka the Elephant Man, and Sally Phillips as Princess Juliana of Bulgaria, was also filmed at Knebworth House.
Featuring strong language, adult humour and some violence, the series is due to leave BritBox soon, but it can also be watched on All 4, Channel 4's on-demand service.
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