When Harry Potter came to the West Country and Gloucester Cathedral turned into Hogwarts

• Watch what happened when our crew wanted to see inside 'Hogwarts' in 2001

Film crews descended on Gloucester Cathedral for the first Harry Potter movie 21 years ago.

The set was shrouded in secrecy but that did not stop the media from all over the world trying to get an exclusive.

The 14th century cloisters were transformed into Hogwarts School of Witchcraft and Wizardry from the record-breaking books by J K Rowling - who grew up in the Forest of Dean.

The vaults and pillars provided the ideal backdrop for the magical boarding school, although some alterations were necessary. The stained glass windows had to be obscured and electrics hidden.

In January 2001, ITV News reporter Tim Hurst got short shrift from the film company when he asked for access to the site.

Tim Hurst: "Can we have a look round?"

Vanessa Davies, Warner Bros: "I'm afraid you can't."

Tim Hurst: "Why not?"

Vanessa Davies (to camera person): "Turn that off, please."

Tim Hurst: "I'm just asking you a civilised question. Why can't we have a look round?"

Vanessa Davies: "Because it's a completely closed set. We've got a blanket policy worldwide. We don't want to ruin the magic for the children so we want everyone to see it in the cinema first."

Tim Hurst: "If I've got a pointed hat on and wore a cloak, could I get inside?"

Vanessa Davies: "I'm saying no more. I'm sorry, you're going to have to wait and see it at the cinema."

Tim and his cameraman did get a sneak peek of one of the stars Warner Bros was trying to keep under wraps, shielded by one of the many umbrellas security staff were using to discourage prying eyes.

It was the late Rik Mayall, who played Peeves the mischievous poltergeist in the franchise.

Until that day, the public was only aware of some of the main stars who had signed up, like Robbie Coltrane (Hagrid) and Julie Walters (Mrs Weasley).

A year on and the cameras - including ITV's - were back near the cathedral grounds for the filming of the second movie in the spellbinding franchise, "Harry Potter and the Chamber of Secrets".

This time the cast were well known and the paparazzi were out in force. Here is a gallery of some of the stars that were spotted that day, 28 January 2002.

Although the cathedral was not used as a setting for the third, fourth and fifth Potter movies, Warner Bros returned to Gloucester in February 2008 for the filming of "Harry Potter and the Half-Blood Prince" - and ITV News was there too.

The historic church once again doubled as Hogwarts School and many local children got the opportunity to act as extras. Many of the Hogwarts students seen in the series were actually pupils themselves, of the independent King's School, just yards away.

Security surrounding the filming was tight, as always, with the staff once again armed with umbrellas ready to shield their charges from media attention.

Since 2001, Gloucester Cathedral has gained many a visiting Potter fan, hoping to retrace the steps of their heroes.

It continues to offer 'Highlights tours', where visitors can trace the various locations - where Harry and Ron defeated the troll, Moaning Myrtle flooded the toilets and the door to the Gryffindor common room and many more magical moments from the movies.

How well do you know your Harry Potter?

Here are 10 West Country connections:

• The author Joanne Rowling was born in Yate near Bristol and was brought up in Tutshill in the Forest of Dean. She named the Tutshill Tornados Quidditch team after the village.

• J K lived near the Gloucestershire market town of Dursley - which she used as a surname for Harry Potter's horrid family - but she never visited and has said that she just liked the sound of the name.

• Harry Potter's ancestors were originally from Gloucestershire - Harry is a descendant of the 12th century wizard Linfred of Stinchcombe near Dursley.

• Lacock Abbey in Wiltshire also served as a filming location, hosting a number of Hogwarts classrooms, including Professor Snape's dreaded Potions lessons.

• Other locations include Symonds Yat in the Forest of Dean, which doubled as a hiding place for Harry, Ron and Hermione in "Harry Potter and the Deathly Hallows Part 1".

• A nine-year-old girl from Somerset spotted a continuity error in Harry Potter and the Goblet of Fire. In October 2000, Laila Banjar from Paulton contacted the publishers to say a character had mistakenly been resurrected and the book had to be reprinted.

• A teenager from Bath got her film debut in Harry Potter and the Goblet of Fire. Angelica Mandy was picked to play Gabrielle Delacour and went on to appear in Vanity Fair, which was partly filmed in Bath.

• In 2001, Jemima Parry-Jones, the owner of the National Bird of Prey Centre in Newent urged J K Rowling to say that owls do not make good pets. Harry Potter had a snowy owl called Hedwig and the centre had inquiries from all over the world.

• A Gloucestershire firm supplied the snow for the Harry Potter films. Snow Business, based in Stroud, can create all kinds of the white stuff from frost and ice to falling snow.

• A first edition of Harry Potter and the Philosopher's Stone was auctioned for £15,000 in Wiltshire in December 2002. The owner, Monica Timms from Swindon originally paid £10.99 and thought that was a bit pricey! There were only 500 copies and they are now going for more than £40,000!