It's hard to believe that it is two decades since the first Harry Potter movie was released.

In the years since Harry Potter was whisked from King’s Cross Station onto Platform 9 3⁄4, his incredible adventures have left a lasting mark on popular culture.

Eight blockbuster Harry Potter films based on the original stories by J.K. Rowling have brought the magical stories to life and today, the Wizarding World is recognised as one of the world’s best-loved brands.

Fans of the bespectacled boy wizard will be able to reminisce on New Year's Day when Harry Potter 20th Anniversary: Return to Hogwarts arrives exclusively on Sky and streaming service NOW. You can also watch all eight movies on Sky Cinema's Wizarding World 20th Anniversary pop-up channel.

But did you know the Harry Potter films are intrinsically linked to Hertfordshire?

With there being 8 Harry Potter films, here's 8 facts about the movies and their magical links to Herts.

1. Warner Bros. Studios Leavesden

Where else could you start than the Hertfordshire home of the Harry Potter movies?

All eight blockbusters were made at the film studios in Leavesden.

Produced by Warner Bros. Unscripted Television in association with Warner Horizon at the iconic Warner Bros. Studio Tour London — The Making of Harry Potter, Harry Potter 20th Anniversary: Return to Hogwarts is executive produced by Casey Patterson.

“There’s magic in the air here with this incredible cast, as they all return home to the original sets of Hogwarts, where they began 20 years ago," said Casey.

"The excitement is palpable as they prepare to take their fans on a very special and personal journey, through the making of these incredible films."

2. Warner Bros. Studio Tour London – The Making of Harry Potter

Just a stone's throw from the actual soundstages where the movies were made, Warner Bros. Studio Tour London – The Making of Harry Potter opened its doors on March 31, 2012.

The tourist attraction offers visitors the ultimate chance to get up close to authentic sets, discover the magic behind spellbinding special effects, and explore the behind-the-scenes secrets of the Harry Potter film series.

Visitors can see the original Great Hall, step into the Forbidden Forest and discover Diagon Alley, all before marvelling at the breathtaking miniature scale model of Hogwarts Castle.

Tickets must be pre-booked at and cannot be bought at the attraction.

3. St Albans Cathedral

Although location filming for the first Harry Potter film didn't take place at St Albans Cathedral, the historic Abbey was used as a backdrop for an early promotional photoshoot involving the then young and unknown cast members Daniel Radcliffe, Rupert Grint and Emma Watson.

4. Rupert Grint

Rupert Grint, who played Hogwarts student Ron Weasley in the hit wizard movies, grew up in Watton-at-Stone and went to school in nearby Hertford.

He later bought a mansion in the Herts countryside in Kimpton.

The actor also joined Ed Sheeran at The Forum Hertfordshire in Hatfield in 2011 to shoot the video for the chart-topping singer's single Lego House.

In the official trailer for Sky's forthcoming Harry Potter reunion, he says: "Well I think this is the perfect time to sit down with everyone and reminisce."

Speaking about his co-stars, he adds: "It's a strong bond that we'll always have. We're family and we will always be part of each other's life."

5. Knebworth House

With its Gothic-looking exterior, it's no surprise Knebworth House was used by Harry Potter's makers for promotional purposes 20 years ago.

During October and November 2001, Knebworth House hosted the international launch of the first Harry Potter film, Harry Potter and the Philosopher’s Stone, which was released as Harry Potter and the Sorcerer's Stone in America.

Knebworth House posted on Instagram: "Many rooms in the house were transformed using furniture and props from the film to create an atmospheric setting in which to interview the actors."

Daniel Radcliffe, who played Harry Potter, Rupert Grint, aka Ron Weasley, and Emma Watson, who starred as Hermione Granger, all visited Knebworth House for the press junket.

6. Hatfield House

Hatfield House's website lists 2011's Harry Potter and the Deathly Hallows – Part 2 as one of the productions filmed on the Hertfordshire estate's grounds.

Daniel Radcliffe movie Victor Frankenstein, which came out in 2015, was also partly shot at Hatfield House.

Radcliffe, as Igor, filmed scenes in the Library with James McAvoy playing Victor Frankenstein.

7. Ashridge Estate

You can walk in Harry Potter's footsteps on the Ashridge Estate, an Area of Outstanding Natural Beauty (AONB) near Berkhamsted. The National Trust estate features in Harry Potter and the Goblet of Fire.

The Frithsden Beeches area of the woods, and in particular a distinctive 400-year-old beech tree, can be seen in the scenes where Harry and the Weasleys head to the Quidditch World Cup.

On the way, they bump into Cedric Diggory, who is hiding up the tree.

Sadly, the gnarled and knotted tree is now split in half and decaying.

8. Mike Newell

St Albans-born film director Mike Newell, who contributes to Return to Hogwarts, directed Harry Potter and the Goblet of Fire, the fourth instalment in the franchise.

The BAFTA award-winning filmmaker, an alumnus of St Albans School, previously directed Four Weddings and a Funeral and was the first Brit to direct a Harry Potter film.

In 2005, he received an honorary Doctor of Arts degree from the University of Hertfordshire.

There is also a film and television studio, The Mike Newell Soundstage, named after the director at the University of Hertfordshire in Hatfield.

About Harry Potter 20th Anniversary: Return to Hogwarts

This highly anticipated retrospective special, to be screened on Sky Max from Saturday, January 1, 2022, invites fans on a magical first-person journey through one of the most beloved film franchises of all time.

The programme reunites Daniel Radcliffe, Rupert Grint and Emma Watson, as well as other esteemed cast members and filmmakers from across all eight Harry Potter films for the first time, to celebrate the 20th anniversary of the franchise’s first movie, Harry Potter and the Philosopher’s Stone.

Zai Bennett, Sky MD of Content UK & Ireland, said: “Twenty years ago we welcomed a little bit of cinema magic into the world as Harry Potter and the Philosopher’s Stone had its big screen debut.

"It’s a franchise like no other, enchanting generations of children and adults alike."

Alumni of the film franchise will join the reunion, including Helena Bonham Carter, Robbie Coltrane, Ralph Fiennes, Jason Isaacs, and Gary Oldman.

Tom Felton, James Phelps, Oliver Phelps, Mark Williams, Bonnie Wright, Alfred Enoch, Toby Jones, Matthew Lewis, Evanna Lynch, and Ian Hart will also take a trip down memory lane.

Producer David Heyman and filmmakers Chris Columbus, Alfonso Cuarón, Mike Newell and David Yates also feature.

Tom Ascheim, president Warner Bros. Global Kids, Young Adults and Classics, said: “This retrospective is a tribute to everyone whose lives were touched by this cultural phenomenon — from the talented cast and crew who poured their heart and soul into this extraordinary film franchise to the passionate fans who continue to keep the Wizarding World spirit alive 20 years later.”