Image source, Durham CathedralImage caption, People still enjoy donning wizard hats for Harry Potter-themed tours

It's 20 years since the boy wizard Harry Potter hit the big screen.

In November 2001, Harry Potter and the Philosopher's Stone was released in cinemas and it was cool for adults to be seen on beaches, buses or trains with their heads in one of the phenomenally-popular children's books.

However, no one location would do to bring the wizarding magic to life when the novels were made into films.

A number of locations including cathedrals, a castle and places of historic interest across England soon had new claims to fame.

Durham Cathedral, Durham CityImage source, Getty ImagesImage caption, The cathedral's Chapter House was used as Professor McGonagall's classroom

Hogwarts School of Witchcraft and Wizardry came to life in various locations, including Durham Cathedral's ancient cloisters in the franchise's first big screen outing.

Also the cathedral's Chapter House was the location of Professor McGonagall's transfiguration classroom scenes.

To celebrate the anniversary, fans are being urged to visit on Saturday from 10:00 to 14:00 GMT and don their wizarding house colours and robes and see if they can spot which places in the cathedral made it to the big screen.

Image source, Getty ImagesImage caption, The cloisters at Durham Cathedral were the perfect setting for wizardingMersey Tunnels, LiverpoolImage source, Getty ImagesImage caption, The Queensway Tunnel featured in The Deathly Hallows Part One

Up to 90,000 vehicles pass through Liverpool's Mersey Tunnels every day, but only one giant on a flying motorbike – with the world's most famous wizard in his side car – has travelled through them.

In 2010, Harry Potter – Daniel Radcliffe – and Hagrid – Robbie Coltrane – turned up in the city to film the dramatic chase scene in The Deathly Hallows Part One.

Fleeing Voldemort and his Death Eaters, in the film they are seen taking a detour through the Queensway Tunnel, narrowly missing the oncoming traffic.

Image source, Visit LiverpoolImage caption, A chase scene was filmed in the iconic tunnel

Merseytravel, which owns and operates the tunnels, was paid £20,000 by Warner Brothers for the use of the Queensway Tunnel.

It donated the money to a children's hospice.

De Vere House, Lavenham, SuffolkImage source, FTP EdelmanImage caption, De Vere House in Lavenham was used as the fictional birthplace of Harry Potter

The 14th Century De Vere House in Lavenham, Suffolk, was used as the birthplace of Harry in the Deathly Hallows Part One.

But it was also the site of something darker – it was also where the young wizard's parents were killed by Lord Voldemort.

It was put up for sale for almost £1m in 2017, but conjuring up a buyer was a struggle and it is currently an attraction on Airbnb.

Image source, FTP EdelmanImage caption, The Grade I-listed house boasts many period features including a massive timber frame and fireplaces

It formed part of Godric's Hollow in the film and was seen with a Christmas tree in the window, opposite a fictional graveyard.

The house is among about 340 listed buildings in Lavenham, considered to be the best-preserved medieval village in England.

Gloucester Cathedral, GloucestershireImage source, Getty ImagesImage caption, Gloucester Cathedral was transformed into a hiding place for the boy wizard and the scene where a troll went on the rampage

Gloucester’'s historic cathedral cloisters were transformed into the corridors of Hogwart’s for the first two films and the Gothic building's lavatorium – a washing place – also features several times.

In the first of the film series, the troll who smashed up the girls' toilets, trapping Hermione, is seen walking along the cloisters, while Harry and Ron hid in the Lavatorium.

The cathedral makes a reappearance in the second film when its North Walk features the words written in blood which announce the Chamber of Secrets has been opened.

A few steps away is where Moaning Myrtle flooding the toilets.

The Lavatorium also provided a hiding place for the boy wizard in Harry Potter and the Half-Blood Prince – the sixth in the franchise – as he overhears Professor Snape saying how he had already taken the unbreakable vow.

More than 170 pupils aged 11 to 18 from the nearby King's School were given a first leg up on the acting ladder and starred as extras in the multimillion-pound production.

The Zoological Society of London (ZSL) Zoo, Regent's ParkImage source, ZSL London ZooImage caption, The reptile house was the perfect setting for Harry's encounter with a python

The Reptile House at ZSL London Zoo is home to an amazing collection of reptiles and amphibians, including snakes, lizards, frogs and crocodiles.

It was thought to be the perfect setting – with its dim lighting – to film Harry's creepy encounter with a talking Burmese python which he frees in the Philosopher's Stone.

In real life, the enclosure filmed is home to a black mamba snake.

Lacock, WiltshireImage source, Getty ImagesImage caption, As well as being used as Hogwarts, Lacock Abbey has featured in BBC period dramas Wolf Hall and Pride and Prejudice

The village of Lacock in Wiltshire has become know as "Harry Potter village" over the years because it was used so many times as a location for the films.

Scenes from the Philosopher's Stone, the Chamber of Secrets, the Half-Blood Prince, and most recently Fantastic Beasts: The Crimes of Grindelwald were all filmed there, probably because of its varied architecture with some buildings dating back to the 14th Century.

Image caption, Lacock Abbey's Warming Room was transformed into the Professor Snape's classroom for potions lessons

Lacock Abbey, one of many locations to become Hogwarts, is a country house with monastic roots and was once the home of William Henry Fox Talbot, inventor of the photographic negative.

Among other filming locations, the abbey's Warming Room was turned into the classroom where Professor Snape's potions lessons were taught.

Scenes from BBC period dramas such as Wolf Hall and Pride and Prejudice were also filmed here, according to the National Trust which owns most of the village.

Glenfinnan Viaduct, Scottish HighlandsImage source, Getty ImagesImage caption, The 19th Century Glenfinnan Viaduct has been used as a location in several films and television series

The Glenfinnan Viaduct in the Lochaber area of the Highlands of Scotland saw the Hogwarts Express travel over it for the filming of the second and third Harry Potter books.

The 19th Century viaduct has been used as a location in several films and television series, including Ring of Bright Water, Charlotte Gray, Monarch of the Glen, Stone of Destiny and The Crown.

After its appearance in the Harry Potter films, British Transport Police warned fans not to walk on the viaduct after several near-misses with trains.

Alnwick Castle, NorthumberlandImage source, Alnwick CastleImage caption, Alnwick Castle now runs "broomstick training" for young fans

Alnwick Castle in Northumberland also starred as Hogwarts School during the Philosopher's Stone and the Chamber of Secrets in 2002.

The Outer Bailey was used as the area where Harry and his fellow students learnt the rules of wizarding sport Quidditch while the Inner Bailey was where Harry and Ron crash-landed the Weasley family's flying car.

Owned by the Duke and Duchess of Northumberland, the castle now offers "broomstick training" to its younger visitors.